New and rare British spiders

Summary

The following species new to Britain are described: Family LINYPHIIDAE Subfamily ERIGONINAE Erigone psychrophila Thorell (male only) Typhocrestus simoni Lessert (male only) Rhaebothorax paetulus (O. P.-C.) (both sexes) Subfamily LINYPHIINAE Centromerus parkeri sp. nov. (male only)

The new county records add 13 species to the Scottish list and eight species to that of Wales.

Species new to Scotland:

• Tibellus maritimus (Menge)

• Pirata uliginosus (Thor.)

• Theridion melanurum Hahn

• Wideria nodosa (O. P.-C.)

• Cornicularia kochi (O. P.-C.)

• Erigone capra Sim.

• Erigone psychrophila Thor.

• Rhaebothorax paetulus (O. P.-C.)

• Ostearius melanopygius (O. P.-C.)

• Porrhomma convexum (Westr.)

• Centromerus parkeri Sp. n.

• Bathyphantes parvulus (Westr.)

• Allomengea warburtoni (O. P.-C.)

Species new to Wales:

• Coelotes terrestris (Wid.)

• Wideria nodosa (O. P.-C.)

• Lophocarenum stramineum (Menge)

• Mecopisthes silus (O. P.-C.)

• Scotargus inerrans (O. P.-C.)

• Typhocrestus simoni Lessert

• Bathyphantes parvulus (Westr.)

• Taranucnus setosus (O. P.-C.)

     

Leeches (Hirudinea) from Ethiopia

Summary

In the collection of Leeches submitted by Dr. Brown I found the following species:

• 1. Glossiphonia disjuncta Moore

• 2. Theromyzon tessulatum (O. F. Müller, 1774)

• 3. Theromyzon cooperi (Harding)

• 4. Batracobdella tricarinata (Blanchard)

• 5. Hemiclepsis marginata (O. F. Müller, 1774)

• 6. Helobdella stagnalis L.

• 7. Parabdella stuhlmanni (Blanchard)

• 8. Limnatis nilotica (Savigny)

• 9. Limnatis africana Blanchard

• 10. Limnatis oligodonta Johansson

• 11. Myxobdella africana Moore

• 12. Salifa perspicax Blanchard

Species No. 3 has been recorded only from Ethiopia; Nos. 1, 4, 7, 9, 10, 11 and 12 are African and Nos. 2, 5, 6 and 8 have been recorded also from Europe, Asia and America.

According to Moore (1939 a, 1958) the following three species are also known from Ethiopia:

• 13. Batracobdella quadrata Moore. African species (ex-Belgian Congo)

• 14. Helobdella conifera (Moore). African species (ex-Belgian Congo, South Africa, Uganda).

• 15. Parabdella garoui (Harding). African species (South Africa).

This is the total number of species of leeches reported from Ethiopia.     

Undescribed anatomical features of the gut of the house cricket,Acheta domesticus L. (Insecta,Orthoptera)

Summary

The following new anatomical features of the gut of Acheta domesticus are described and discussed:

• 1.A thin-walled dorsal evagination of the oesophagus, which may serve to circulate digestive fluid in the crop.

• 2.Lateral invaginations of the wall of the posterior oesophagus and anterior crop, separated from the circular muscle layer and allowing considerable enlargement of the foregut during feeding.

• 3.Strands of muscle and connective tissue linking the caeca and crop to the thoracic cuticle, innervated in part from the prothoracic ganglion, which may serve to register the extent of gut filling.

• 4.Evidence from the arrangement of the gut tracheae and nerves of rotation of parts of the gut from their original ancestral position, the gizzard and caeca being rotated through 90° and the crop through 180°. It is suggested that these rotations have been necessary to accommodate the gut components to changes in the shape and proportions of the body during the evolution of the cricket lineage.

     

Two species of caligid copepods (Crustacea) parasitic on marine fishes of Venezuela,with discussion of Metacaligus Thomsen, 1949

Summary

O, I and II group flounders showed a regular increase in length and weight between April and September, but did not grow during the winter months. These immature fish showed highest condition factors and calorific values in summer and lowest in winter. III and ? IV group flounders had highest condition factors and calorific values in winter prior to spawning and lowest when they returned to the estuary as spents in April. Males matured towards the end of their third year and females towards the end of their fourth. Gonad development started in October and peak gonad weights were attained in November (males) and February to April (females).

Diurnal variations in the numbers of fish were very marked on the Sleek of Tarty where larger numbers were caught at night. Little diurnal variation was noticeable on the Forvie Bank mud flat.

Largest numbers of flounders were recorded between May and September when the population was 50–100 times larger than the winter low (January to March). Estimates of the total population size are given, based on observed densities on underwater transects.

Seasonal changes in the population of flounders on the intertidal mud flats were influenced by four major migrations:

• (1)A spring immigration (April and May) of immature (except the O group) and spent fish, the spent females being present in significantly greater numbers than males.

• (2)O group flounders entered the estuary in late June early/July, approximately two months later than the immigration of O group plaice.

• (3)A proportion of III and ? IV group flounders left the mud flats in July and tagging data suggested that they left for the sea.

• (4)The winter emigration of all age classes started in October and continued through the winter, leaving a small population composed mainly of O group and maturing fish. Cormorants preyed mainly on I and II group flounders in winter and probably accounted for the low numbers of these age groups at this time.

     

IV.—On specific character,fecundation, and abnormal development in Œdogonium

Summary

• 1. A morphological study of five body regions of the Lepidoptera has been made, these being (a) the radial system of the mesothoracic wing, (b) the mesothoracic sternopleural region, (c) the ventral thoraco-abdominal articulative (and adjacent) structures, including the integumental components of the tympanum where present, (d) the dorsal thoraco-abdominal articulation, etc., and (e) the metathoracic furca or endosternite. These regions were selected because the nature of the variation they exhibit suggested that, of the much larger number of regions primarily investigated, they are the most likely to provide information on the evolution of the higher taxa in the order. None of these regions had been investigated at all fully previously, and therefore a considerable amount of basic morphological study was necessary as a preliminary to phylogenetic discussion. This morphological work has been extended to include the primitive Lepidoptera (with the Trichoptera) in the case of the mesosternopleural region, and in the regions of thoraco-abdominal articulation, in order to clarify basic homologies where these were obscure in the Ditrysia.

• 2. Included also in the preliminary morphological treatment are two other body regions, the variation of which is not complex, and can be more briefly described. These regions are the prothoracic sclerites and the metanotal subdivisions—both of these showing interesting variation throughout the order which can be easily interpreted from the phylogenetic standpoint.

• 3. Following reference to the basic morphology of each region studied, a broad outline of the evolutionary dynamics of each character complex is given in order to provide a basis for discussion of the evolutionary trends manifested within the superfamilies.

• 4. In sections four and five of this work, the character complexes which were the subject of morphological study earlier are examined further with regard to their dynamics as manifested within each of the Ditrysian superfamilies. The formation of the concepts which are outlined here is based on consideration of all information derivable from all of these character complexes along with previously published information on other aspects of Lepidopterous anatomy. Resulting from this, a re-organization of the superfamilies has been possible on a phylogenetic basis. The chaotic state of the past literature on the classification of the Lepidoptera, the result of superficial taxonomic work, renders the comparison of the present system with previous ones clearly impossible within the scope of the present paper, but it is noted that many of the superfamily groupings do not differ very widely from those in some of the more comprehensive early studies, such as Forbes (1923). Through lack of material, no radical re-organization of the primitive Ditrysian superfamilies included in the Tinaeoid complex has been attempted, and for the same attempting to convey a very great deal of information by means of varied labelling of the two components of the suture. Reference both to the text, and to the figures given in the introductory (morphological) section of this paper, should however, enable anyone to appreciate these factors from the figures given. (3) Abbreviations used with reference to wing veins and pupal tracheae follow the standard Comstock-Needham system, apart from the identification of Cu2, which follows Tillyard's (1969) interpretation.

Note also that a few of the less common structures have been explained with the captions to the figures.