508 MR. R. I. POCOCK OX THE ARACH.VIUS COLLECTEU [JuUti^l, 



lacustris the spines are relatively few in number and more scattered. 

 Coxae thickly hairy below, coxa of 3rd with a band of close-sefc 

 short spikes. Legs 4, 1, 3, 2 ; tibia of 3i-d thick, its width slightly- 

 exceeding its superior length ; width of femur of this leg about 

 two-thirds its superior length (in lacustris barely more than half). 



Measurements in millimetres. — Total length of trunk 33, of 

 carapace 14 (with mandibles 19); length of palpus 21, of 1st leg 

 24, 2nd 22, 3rd 23, 4th 31 (all from base of femur) ; paiella and 

 tibia of 1st 10, of 4th 12; tarsus and protarsus of 4th 10. 



Log. Taru and Machuma in the Taru desert {ttipe). A female 

 example from each of these localities. 



This species and Acanthodon Ucustri<<, recently described from 

 Kinyamholo, Lake Tanganyika (P. Z. S. 1897, p. 731), may be 

 distinguished by the following characters : — 



a. Labial teeth 4-.'') ; externa! side of tibia of '2nd leg armed 



with short robust spinea ; coxiB of legs densely hairy 

 below, that of .3rd leg with an oblong area of close-set 

 spiniiles; legs shorter, protarsus of 4t.h rather less in 

 length than twice the width of the ocular area ; width 

 of ocular area exceeding by a little the length of the 

 upperside of the 3rd tibia; width of 3rd tibia equal to 

 its length robustus, sp. n. 



b. Labial teeth 2; external surface of 2nd tibia without 



short stout spines ; coxfe of all the legs almost sparsely 

 hairy below ; legs longer, protiirsus of 4th exceeding 

 twice the width of the ocular area, which is slightly less 

 than the length of the 3rd tibia ; width of 3rd tibia ex- 

 ceeding its length laacstris Poc. 



It appears to me impossible to say whetlier the species described 

 by Gerstiicker as Idiops compacius belongs to the genus Acanthodon 

 oi- to the allied genus Helirimomerus. It was procured at Dafeta, 

 Kilimanjaro, a locality which at first suggests the possibility of 

 identity between it and Acanthodon robustus. But according to 

 Gerstacker, compactus has only a pair of labial teeth as in lacustris, 

 and is much smaller than rohistus, the total length of carapace 

 and mandibles being 13-5 mm. Moreover the legs of the 3rd pair 

 are said to be shorter than the rest, and the palpi as long as the 

 legs of the 1st p;iir — characters which do not apply to robustus. 



Family Aegiopid-«. 

 G-enus Nephila Leach. 

 Nephila madagascaeibnsis (Vinson). 



Epeira madar/ascariensis, Vinson, Araueldes des lies Reunion, 

 Maurice et Madagascar, p. 191, pi. vii. ( = N. argyrotoxa Gerst.). 

 Loc. Maziwa Mitatu in the Taru desert. 

 Widely distributed throughout East Africa. 



Nephij.a sijmptuosa Gerstaeker. 



Nephila sumptuosa, Gerstaker, A'^on der Decken's Beisen iu Ost- 

 Afrika, iii. 2, p. 501, pi. xviii. fig. 12. 



