84 ME. T. SCOTT ON ENTOMOSTRACA 



same on both sides in the female. Anterior antennae 21<-jointed; the two basal joints are 

 moderately stout and large, several of the succeeding joints are very short, while from 

 the 16th to the end all the joints, but especially the 18th and 19th, are elongate and 

 slender. The approximate proportional lengths of the joints are shown in the formula : — 



7.10.1.1.1.1.2.2.3.3.3.4..5.5.6.9.9.10.11.8.7.7.6.6 

 T 2 3 -4 5 6 7 « y 10 11 12 13 1-1 15 16 17 18 liJ 20 21 i'l> 23 24' 



The middle joints of the right male antenna are slightly swollen ; the 3rd joint has a 

 number of indistinct articulations ; the 9th and 10th joints, between which is a dis- 

 tinctly hinged articulation, are furnished with marginal appendages that are toothed 

 along the upper edge ; the free portion of the appendage of the 9th joint extends hack- 

 ward the whole length of the preceding joint, while that of the 10th joint projects only 

 a little forward beyond the joint to which it belongs ; the 7th joint is about twice the 

 length of the preceding one, and equal to the next ; the 9tli is a little shorter than the 

 8th, and about half the length of the 10th ; the 11th is about two thirds the length of 

 the 10th, and equal to the next two together. The marginal teeth on the appendage 

 of the 9th joint spring from the distal end of a quadrangular base ; the basal parts of 

 the teeth are closely applied to each other, end to end, as shown in the enlarged drawing ; 

 the marginal teeth on the appendage of the lOtli joint are somewhat conical in shape, 

 and are slightly curved forward. The apical portion of the posterior foot-jaw is 

 4-jointed (PI. VI. fig. 39). The first joint of the right tif th foot of the male (fig. il) has a 

 broad triangular outline, and part of the outer angle is, as it were, cut off to form an 

 attachment for the next joint; the last joint is considerably swollen, so that the inner 

 marffin forms an elevated arch ; a stout curved and snoon-like claw is articulated to the 

 exterior portion of the joint, and the claw is opposed by a produced basal process so as 

 to form a prehensile organ closely resembling the beak of a bird, and giving to the 

 whole joint somewhat the appearance of an enlarged " bird's-liead process " observed in 

 species of Polyzoa. The last joint of the left foot has a bifid apex and a small blunt- 

 pointed tooth on its outer margin ; part of its inner surface is covered with fine cilia, 

 while the inner angle of the second joint is produced in the form of a ringed (? sexual) 

 process. Fifth pair in the female simple, the basal joints stout, with a small seta on 

 the proximal half ; outer branches elongate, attenuated towards the pointed apex, and 

 furnished exteriorly with a comparatively large subapical spine, and with a minute spine 

 on the interior edge. The inner branches are small, curved, stoutly spiniform, and not 

 half the length of the outer In-anch. The abdomen in the male is composed of four, in the 

 female of two segments, as shown in PL VI. fig. 12 and PI. VII. fig. 5. In the female the 

 caudal stylets are unequal in length ; the fourth caudal seta, counting from the outside, 

 in both male and female, but especially the former, is considerably long er than the others 

 (fig. 42). In all the female specimens obtained an apparently structureless membrane 

 of an irregular outline covered the greater portion of the abdome n, and extended beyond 

 the stylets to about halfway over the caudal setae, as shown in tig. 42. 



HahiUd. Libreville, Gaboon Uiver, in surface tow-net material collected after midday, 

 January 28th. 



