1897.] MB. E. I. POCOCK ON ETHIOPIAN SPIDEES. 771 



Measurements in millimetres. Total length 22 ; length of cara- 

 pace 10, width 9 ; length of 1st leg 35, of 2n(i 32-5, of 3rd 31, of 

 4th 41 ; patella and tibia of 1st 12-8, of 4th 13-5 ; protarsus of 

 4th 12. 



Loc. W. Africa (Kei/serling coll.). Two male examples. 



These two examples are the specimens referi-ed to by Karsch 

 (Berl. eut. Zeits. 1884, p. 350) as the males of Dipluralongipalpis, 

 Karsch (Zeits. Naturwiss. (3) iv. p. 564, 1879), which was based 

 upon a female from the same area. But the specimens belong 

 neither to the genus Diplura nor j'et to the family Dipluridse. 

 Moreover, the evidence that they are in reality the males of the 

 species named Jonyipalpis is to my mind somewhat slender. 



[P.S., Juhi 30th, 1897.— Since this paper was written and read 

 before the Society in the middle of June, I have discovered in 

 some of the African genera of Theraphosinffi an organ which 1 

 believe furnishes a key to their affinities of greater value than 

 those relied upon for grouping them on p. 745. This organ is a 

 curious system of hairs, certainly of a stridulating nature, deve- 

 loped on the anterior side of the upper half of the coxa and 

 trochanter of the 1st and in a lesser degree of the 2nd leg also. 



In the diagnosis of Hysterocrates (jirjas mention is made of a 

 " curious brush of hairs on the upper side of the coxa and 

 trochanter" of the limbs in question. When the 1st leg of this 

 species is removed and the organ submitted to closer inspection, 

 under a lens of low power, it will be seen that the so-called bnish 

 of hairs consists of a fringe of close-set m bitish feathery hairs. 

 On the trochanter this fringe overshadows and probably protects 

 from dirt a number of long, erect, but apically curled stoutish 

 spines arranged somewhat irregularly in two rows. On the coxa 

 the hairs of the fringe become stout and spiniform where, at the 

 base of the segment, they extend downwards towards the coxal 

 suture, and distally some "of them become isolated so as to have 

 perfect freedom for vibration. But in addition to these whitish 

 plumose spines there are two long, stout, black, simple spines, the 

 larger being clavate and lying amongst if not above the fringe, 

 the other being situated below it and not expanded at its distal 

 end, but sharply pointed. Below the suture the bases of the 

 upstanding bristles are very stout, black, and shining, while 

 amongst them arise some delicate erect hairs with shining hyaline 

 clavate tips. The large bristles that lie above the suture of the 

 coxa are set in vibration when this segment is rubbed against the 

 adjacent surface of the coxa of the pedipalp, the distal half of 

 which is covered with hairs, amongst which arise a number of long, 

 stout but pointed spines. Similarly, the spiniform bristles on the 

 trochanter are rubbed against the posterior aspect of the tro- 

 chanter of the pedipalp, which is covered with stiff straight hairs. 

 When the spider is allowed to dry after removal from alcohol, the 



