324 



Mr. F. 0. P. Cambridsie on 



islands of the Greater and Lesser Antilles and the more adja- 

 cent regions of the mainland all round. 



If it be asked what are the final tests of a distinct species 

 of spider, one can only say that a long course of experimental 

 interbreeding under perfectly natural conditions, settling 

 which would breed together and which not, might solve the 

 problem. Such an investigation being impossible, one has to 

 fall back on the com})arative anatomy of the genitalia. If 

 these are identical in a number of individuals of different sexes, 

 the latter are held to belong to one and the same species. If 

 not structurally identical, then the forms are regarded as 

 distinct species, on the supposition that two different forms of 

 male organ are not adapted to the fertilization of one form of 

 the female organ. 



Fam. Theraphosidse. 

 LtroSCELUS, gen. no v. 



Femur iv. not scopulate on inner side. Tarsal pads not 

 divided ; scopula interspersed with a few scattered hairs only 

 towards the base. Protarsus i. scopulate to base, with a single 

 spine on inner side only at the base. Apex of tibia i. bical- 

 carate. Protarsus iv. scopulate at extreme apex only. Legs 

 spinulose, especially iii. and iv. Apical third of labium and 

 inner anterior angle of coxa of pedipalp spinulose. Tro- 

 chanter of leg i. with 10-12 stout clavate stridulating- spines 

 on the inner side, extending over the upper two thirds of the 

 segment ; opposed to these are 15-16 long, stout, slightly 

 clavate spines, situated on the outer side of the trochanter of 

 the pedipalp, extending over the central half of the segment. 



Lyroscelus Bonhotei, sp. n. (PI. VII. figs. 6, 6 a.) 



Colour. Carapace clothed with a very pale bronze covering 

 of shaggy hair. Mandibles brown, with a basal dorsal 

 clothing of the same pale bronze hairs. Legs clothed with 

 coffee-brown hairs, interspersed on the protarsi and tarsi with 

 long scattered rufous hairs. Femora and jjatellae of legs, 

 especially i. and ii., clothed with golden- bronze hairs over the 

 dorsal and externo-lateral areas. 



Abdomen clothed with darker coffee-brown hairs, inter- 

 spersed, especially towards the spinners, with long rufous 

 hairs. 



Sternum and coxse of legs coffee-brown ; coxae of pedipalp 

 and fringe on fang-groove of mandibles bright rufous. 



Measurements. — Carapace 18 x 15 millim. ; pat. + fib. i. and 



