XIII.—Notice of three new species of Sinusigers,a genus of Brachiocephalous Mollusks

Summary

The reproductive organs of the male and female Gryllodes sigillatus, together with their associated muscles, are described in detail. The male reproductive organs are characterized by the presence of the accessory gland tubules and the absence of sperm vesicles. The presence of a pair of lateral pouches on the genital chamber and a chitinous bursa copulatrix at the posterior end of the spermathecal duct are peculiar features of the female reproductive organs. The testes and the ovaries are attached by the testicular and ovariolar ligaments respectively to the tergum of the first abdominal segment.     

On the taxonomic status of the highly endangered Ponto-Caspian gastropod genus Caspia (Gastropoda: Hydrobiidae: Caspiinae)

Caspia is an endemic Ponto-Caspian Basin genus of hydrobiid gastropods. Around a dozen nominal species of Caspia have been described to inhabit the Caspian Sea while four species occupy a restricted zone in the lower part of the rivers flowing into the Black Sea and the Sea of Azov. Scanning electron microscopic study of the protoconch and radula morphology of two Caspia species from the Azov–Black Sea Basin allows re-evaluation of the taxonomic rank and attribution of the genus. The adult shell geometry and characters of ornamentation do not enable clear demarcation of these species of Caspia but the protoconch parameters do allow their differentiation. Available morphological data on Caspia and the related genus Caspiohydrobia are interpreted here as confirmation of the subfamilial rank of Caspiinae in the family Hydrobiidae, in contrast to the previous affiliation of this group with Pyrgulidae.     

A new species of Thais (Mollusca: Neogastropoda: Muricidae) with direct development from northwestern Australia

Thais wutingi, a new species of Muricidae, is described from rocky and mangrove shores in the vicinity of Darwin, northern Australia. It is relatively common where it occurs but the species may have previously been mistaken for T. gradata (Jonas) or T. javanica (Philippi). The new species differs from the latter two species in having a penis with a narrow groove along the greater curvature of the penial base. The larvae of T. wutingi undergo direct development, hatching from egg capsules as crawling juveniles, in contrast to the majority of Thais (s.l.) species found in the tropics which have planktotrophic development. Its mode of development may explain the relatively restricted geographical distribution of this species, which is confined to the north and northwestern coasts of Australia.     

Macro- and microscopic morphology of the reproductive system of Leptinaria unilamellata (d’Orbigny, 1835) (Mollusca: Pulmonata: Subulinidae)

Many tropical terrestrial gastropods, such as Subulinidae, are recognized and classified by their shells, as is the case for Leptinaria unilamellata (d’Orbigny, 1835), a hermaphroditic pulmonate snail restricted to tropical America. We aimed to characterize the morpho-anatomy and histology of the reproductive system of L. unilamellata. We compared the results obtained from L. unilamellata with the available data on the reproductive system of other subulinid species. The main distinctive characters are those of the penial complex, such as the proportion of the length of the penial complex and the length of the free oviduct, presence of a flagellum, site of insertion of the bursa copulatrix duct relative to the site of insertion of the penial complex and presence and extension of the penial sheath.     

New genera of pseudocerotid flatworms (Platyhelminthes; Polycladida) from Australian and Papua New Guinean coral reefs

Two new genera, Maiazoon nov. gen. and Phrikoceros nov. gen. are described respectively from Madang, eastern Papua New Guinea and the Great Barrier Reef, Australia. The monotypic genus Maiazoon resembles Nymphozoon Hyman, 1959 since it possesses multiple male reproductive systems and multiple female pores although the latter genus lacks a penial stylet and sucker. Phrikoceros, with five new species, morphologically resembles Pseudobiceros although it possesses only one male reproductive system as found in Pseudoceros.     

Four new species of terrestrial earthworms belonging to the genus Amynthas (Megascolecidae: Oligochaeta) from Taiwan with discussion on speculative synonyms and species delimitation in oligochaete taxonomy

This paper describes four new species of earthworms, Amynthas shinanmontis sp. nov., Amynthas chilanensis sp. nov., Amynthas bilineatus sp. nov., and Amynthas cruxus sp. nov. from Taiwan. Amynthas shinanmontis is sexthecate and parthenogenetic with individuals with various levels of degeneration of spermathecae and male reproductive organs. It occurs at elevations of 1700–2700 m in the Central Mountain Range in southern Taiwan. Amynthas bilineatus and A. chilanensis are athecate and also parthenogenetic. They occur, respectively, at elevations of 1000 m in the central region and 1325 m in the northeastern region of Taiwan. Amynthas cruxus is octothecate, amphimictic, and occurs at elevations of 900–1700 m in southern Taiwan. This paper also discusses confusion and dilemma caused by uncertain, speculative synonyms and parthenogenetic morphs in species delimitation in oligochaete taxonomy, and recommends the use of absolute synonyms and phylogenetic species concept.     

Five new Polycladida (Platyhelminthes: Acotylea) species from the Aegean Sea with remarks on the prostatic structures

Five species of polyclads, Imogine melihertani sp. nov., Pseudoplanocera izmirensis gen. et sp. nov., Izmira cinari gen. et sp. nov., Izmira turkeyi sp. nov. and Pseudodiscocelis aegeanensis gen. et. sp. nov., were collected in Izmir Bay, Turkey, Aegean Sea. I. melihertani is characterized by an anchor-shaped seminal vesicle, penis papilla, and ciliated male and female atria. P. izmirensis possesses spermiducal bulbs, a free prostatic vesicle, cirrus bulb, armed cirrus and Lang's vesicle. The genus Izmira is established based on the presence of a penis rod, true seminal vesicle, an interpolated prostatic vesicle of atomata-type and vagina bulbosa. Izmira cinari has an elongated body; a pointed penis and the oviducts enter the vagina bulbosa separately. Izmira turkeyi is characterized by an oval body, rod-shaped penis and the oviducts join before entering the vagina. Pseudodiscocelis is characterized by prostatoid organs, a lobed penis and ciliated and glandular cells in the male antrum.     

A new species of Crepidula (Mollusca: Mesogastropoda: Calyptraeidae) from Chile: additional characters for the identification of eastern Pacific planar Crepidula group

A new species of Crepidula is described. It was collected together with Pagurus edwardsii Dana and Pagurus perlatus H. Milne Edwards, inhabiting the inside of empty shells of Tegula euryomphala Jones and other gastropods. The shell is low convex-oval in juveniles, low convex-oblong in males and concave-oblong elongated in females. In the adult phases the apex projects slightly at the posterior border. The sinusoidal septum is ‘V’ shaped at its centre, with a smooth sulcus in the left quarter. The osphradium has 2–13 digitiform leaflets according to phases of the life cycle. The characteristically thin, external-lateral teeth of the taenioglossate radula possess a row of denticles. In addition, evidence is given that: (1) males have a lanceolate penis with a spermatic tube; (2) the intracapsular-embryonic development starting with many embryos, occurs with a decrease at the larvae-protoconch stage, each one with an adhered-vitelline mass, and culminates with a few prehatching juveniles of 1 mm size. In the expression of the consecutive-protandric hermaphroditic sexuality, the male phase is truly separated from the female phase by a transition period at the population level. The shell and radular morphology, intracapsular development and ecological antecedents allow the proposal of Crepidula coquimbensis as a new species, and suggest a future taxonomic revision of the group based, moreover, on osphradium structure and new characters of the reproductive system, such as penis morphology.     

Two new marine species from South Korea with remarks on the family Stylochidae (Acotylea,Polycladida, Plathelminthes)

Two new species of acotylean Polycladida are described from Korea, Munseoma maculata gen. et sp. nov., Callioplanidae, and Crytostylochus koreensis sp. nov., Stylochidae. Munseoma maculata is characterized by a small free prostatic vesicle but only indistinctly cut off from the ejaculatory duct; a Lang's vesicle is present. Crytostylochus koreensis possesses a prostatic vesicle with tubular lining of radial arrangement. Each papillate tube is connected via a glandular duct to a single extra‐vesicular gland attached to the muscular wall of the prostatic vesicle. That morphological feature forces discussion of the relationships within the family Stylochidae. Consequently, type material of other stylochids deposited in the museums of Hamburg, Vienna, and Stockholm was borrowed to investigate the genital organs and, in particular, the interior lining of the prostatic vesicle. Based on these analyses, two new types of prostatic lining are defined, the polyglandular type and the monoglandular type. The monoglandular type is defined as having an oval to elongate prostatic vesicle with tubular lining and extra‐vesicular glands. Each extra‐vesicular gland is connected via a glandular duct with a single tube. The polyglandular type is defined as having a mostly roundish oval prostatic vesicle with long‐fingered extensions, more or less horizontally directed distad, and numerous extra‐vesicular glands. Each long‐fingered extension is connected via several glandular ducts of extra‐vesicular glands. Based on these new characters, the family Stylochidae is newly defined.     

Morphology and biology of a new Rhynchospio species (Annelida: Spionidae) from the South China Sea,Vietnam, with the review of Rhynchospio taxa

Adults of a new spionid polychaete, Rhynchospio nhatrangi, inhabit sandy tubes on muddy sand intertidal flats in an estuary of Nha Trang Bay, southern Vietnam. The worms are up to 8 mm long and 0.5 mm wide for 55 chaetigers. They are unique among spionids in the changes in the arrangement of hooks during ontogenesis: first development of tridentate hooks in neuropodia from chaetiger 10, later loss of hooks in chaetiger 10, and replacement of tridentate hooks by heavy unidentate hooks in neuropodia of chaetigers 11–14. Adults are simultaneous hermaphrodites having sperm in chaetigers 11–14 and oocytes from chaetiger 15 to 23–33. Spermatozoa are introsperm, about 300 µm long. Oocytes are about 120 µm in diameter, with a thin and smooth envelope. Fertilization and early larval development occur in a hatchery formed by elongated dorsal capillaries on the posterior chaetigers. Larvae escape from the hatchery probably when they have developed four chaetigers and then continue development in seawater, feeding on the plankton. When larvae have grown to 14–15 chaetigers, they likely undergo gradual metamorphosis and settle on the bottom. Metameric nuchal organs, glandular pouches in neuropodia, metanephridial segmental organs, hermaphroditism, sperm, and early larval morphology are described here for the first time for Rhynchospio species. An identification key is provided to eight currently recognized Rhynchospio species.     

Reflections on the genus Amaga Ogren and Kawakatsu 1990, and description of a new genus of land planarian (Platyhelminthes: Tricladida: Geoplanidae)

Amaga amagensis, the type species of the genus Amaga, and Amaga bogotensis are re-described. Detailed analysis of the morphology of A. amagensis revealed important taxonomic features, such as testes located dorsally to the supraintestinal parenchymal muscular layer, and secretory accumulations opening through the lateral margins of the body. These characters, as well as other morphological features, are discussed, culminating in an emendation of the generic diagnosis of Amaga. Amaga bogotensis exhibits a characteristic set of morphological features, namely an eversible penis, a male atrium lined with large musculosecretory papillae, and independent muscular coats around both male and female atrium. Therefore, a new genus is proposed for this species.     

Smicridea McLachlan (Trichoptera: Hydropsychidae) from northwestern Argentina and Bolivia: new species,redescription, association and new records

Four new species of Smicridea (Rhyacophylax) are described from Argentina and Bolivia. Smicridea (Rhyacophylax) bifida sp. nov., S. (R.) elisae sp. nov. and S. (R.) valeni sp. nov. are described from the male; S. (R.) thermophyla sp. nov. is described as the first species of Smicridea from thermal springs. The larva and pupa of S. (R.) thermophila were associated using the metamorphotype method. New distributional records of S. (R.) dithyra, S. (R.) atrobasis, S. (R.) peruana and S. (R.) pampeana are included. Morphological characters of male S. (R.) peruana that were not mentioned before are included. Illustrations of all taxa named in this paper are included.     

Bostryx tortoranus (Doering, 1879) species complex (Gastropoda: Stylommatophora: Bulimulidae), a review of taxonomy and distribution of endemic species from Argentina

Morphology of the shell, radula, jaw, anatomy and sculpture of the inner wall of the reproductive system are described and compared for three species belonging to the Bostryx tortoranus species complex. On the basis of these characters, the following changes are proposed: Bostryx martinezi (Hylton Scott, 1965) is removed from synonymy with Bostryx tortoranus (Doering, 1879) and Bulimulus (Scansicochlea) cicheroi Hylton Scott, 1967 is transferred from synonymy with B. tortoranus to synonymy with B. martinezi. As a result of these changes, the number of species of Bostryx known from Argentina has increased to 19 species. Bostryx tortoranus and B. martinezi are redescribed, also the radula and anatomy of Bostryx rudisculptus (Parodiz, 1956) are described for the first time. The main distinctive morphological characters of the three species are: the structure of the shell’s protoconch and teleoconch, radular morphology, location of the secondary ureter opening, the length of the free oviduct with respect to the vagina and the epiphallus with respect to the penis and the bursa copulatrix duct’s inner wall sculpture. Bostryx martinezi and B. rudisculptus have restricted distributions and are ecologically endemic, whereas B. tortoranus has a wide distribution and is located in different dry ecoregions.

http://zoobank.org/urn:lsid:zoobank.org:pub:A2F21A37-E0ED-454F-A63D-EEC1804D7DFA     

Taxonomy of the genus Tantunema Siddiqi, 1982 (Dorylaimida: Tylencholaimidae) with description of one new and two known species

One new and two known species of the genus Tantunema Siddiqi, 1982 are described and illustrated. Tantunema indicum sp. nov. is characterized by having a small body (length 0.32–0.45 mm); lip region cap-like, set off by slight constriction; odontostyle 6–7 µm and odontophore 8–10 µm long; pharyngeal expansion gradual, expanded part occupying about 35–41% of total neck length, lumen of posterior expanded part widened and thickened; female genital system mono-opisthodelphic, anterior genital branch absent; tail short, hemispheroid, 0.8–1.1 anal body diameter long. Tantunema pakistanense (Timm, 1964) comb. nov. (=Tylencholaimus pakistanensis Timm, 1964) and Tantunema intermedium (Peña-Santiago and Coomans, 1996) Andrássy, 2009 are redescribed. A diagnostic compendium and key to species of the genus is also provided.     

A new species of Grania (Enchytraeidae,Clitellata, Annelida) and redescription of Grania pusilla from a rocky shore in SE Ireland

Two species of marine Enchytraeidae belonging to the genus Grania Southern, 1913, Grania mira sp.nov and Grania pusilla Erséus, 1974, are described from the rocky shores of southeast Ireland. Grania mira has distinctive muscular modifications of the male ducts. Grania pusilla which was previously reported only from the coasts of Norway and Sweden by Erséus (1974), is completely redescribed, including information on many additional morphological characters noted from recent taxonomic literature on Grania. It is reinstated to the level of species. The species has a penial stylet and a large glandular penial bulb. Differences in setal distribution between specimens of G. pusilla from Ireland and those from Norwegian and Swedish populations are attributed to geographical separation limiting genetic exchange. This is the first report of Grania in Ireland since Southern's discovery of Grania maricola in 1913. Grania maricola shares a structurally simple penial bulb type with G. pusilla, but the species differ in spermathecal shape, spermathecal ectal pore position and vas deferens length.