234 BRITISH 



species G. pteropliorus. The dorsal cuticle of the noto- 

 gaster is almost always more or less rough; in such 

 species as G. plumiger and its allies it is very rough, or 

 granular, and studded with little bifid or trifid points. 

 In such species as G. spinipes and G. domesticus it is 

 much smoother, rather more like chamois leather ; but 

 it is not ever polished or really smooth in any known 

 species. The bursa copulatrix forms a tubular projec- 

 tion in the centre of the hind margin, but not usually 

 on the actual margin; rather on the notogaster close 

 to the margin, in the females throughout the genus. 

 This projection may be very short, as in G. Grameri 

 and G. sciurinus ; or it may be long, as in G. platygaster 

 and G. domesticus. It sometimes has the posterior 

 edge cut into short labia. 



The Legs vary so much in length and thickness in 

 different species that no general rule can be indicated. 

 The tarsi are ordinarily the longest joints, occasionally 

 as long as all the other joints put together, but some- 

 times very little longer than the tibiae. The ambula- 

 crum generally consists of a medium-sized caroncle and 

 a very minute claw, so small very often as to be diffi- 

 cult to see. The legs are often provided with pec- 

 tinated, serrated, plumose, or villous hairs or scales; 

 but these are not usually numerous, the legs being pro- 

 vided with setiform hairs as well. In G. Grameri and 

 G. sciurinus the legs of the male also bear some thin, 

 transparent, chitinous laminae, which in the former 

 species are mostly deeply serrated on their distal edges 

 (PL XVII, figs. 8, 9). 



The Ventral Surface. The epimeral skeleton is 

 usually well developed; the epimera are often joined 

 to the sternum or to a chitinous band, which often 

 surrounds the vulva, and sometimes forms a semicircle 

 in front of the penis. In species like G. domesticus 

 the development of the epimera is weak. The vulva is 

 sometimes placed between the coxae of the second and 

 third pairs of legs, in which case it is usually large, 

 surrounded by a stiff chitinous ring, and consists of 



