20 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 121 



Shell dimensions (in mm) are as follows: 



collector specimen greatest length greatest height remarks 



Brady and Norman A 1.34 0.85 mature male 



B 1.35 0.81 



MuUer 1 1. 30 q. 80 



2 1. 28 0. 78 



3 0. 94 0. 60 instar 



Brady and Norman (1896, p. 659) give measurements of length as 

 1.6 mm and height as 1 mm for specimen BM 1900-3-6-452; because 

 of the poor condition of the mounted specimen, I was unable to 

 measure it. 



MiiUer (1894, p. 211) gives the length of the male as 1.3 mm. 



First antenna (fig. 9i) : First joint with clusters of spines on medial 

 sm-face; 2nd joint with clusters of hairs on medial surface, short spines 

 projectmg from ventral and dorsal margins, and distally with a dorsal, 

 ventral, and lateral bristle; 3rd joint with clusters of hau-s on medial 

 surface and 1 ventral and 2 dorsal bristles; 4th joint with clusters of 

 hairs on medial sm-face and 2 dorsal and 4 ventral bristles distally; 

 5th joint inferred to be inserted between 4th and 6th joints bearing sen- 

 sory bristle with broad base and numerous filaments; 6th joint with 

 medial bristle distally; end joints with 2 long stout c- and f-bristles, 

 1 short spinous dorsal a-bristle, and 2 long b- and g-bristles with 

 filaments and 2 bare d- and e-bristles. 



The above description of the 1st antenna differs from Brady and 

 Norman's (1896, p. 660) in having 2 rather than 1 bristle on the dorsal 

 margin of the 3rd joint and in having a total of 7 rather than 6 bristles 

 on the end joint. The 1st antenna on slide no. 1900-3-6-452 con- 

 taining a specimen dissected by Brady and Norman confirms the 

 presence of 2 dorsal bristles on the 3rd joint and a total of 7 bristles on 

 the end joint. 



Second antenna (figs. 9^^ I; lOa) : Endopodite (fig. Qk) with 3 joints: 

 1st joint with 5 proximal bristles and 1 distal bristle; 2nd joint elongate 

 with 2 bristles near middle; 3rd joint prehensile with a long slender 

 bristle about one-third distance from proximal end of joint and 2 

 short bristles and about 5 crescentic ridges at distal end. Exopodite 

 with 9 joints; 1st joint elongate with small medial spine distally; 2nd 

 joint about one-third length of 1st with spined bristle reaching 6th 

 joint; 3rd joint about twice length of 2nd; joints 4-9 trapezoidal,°each 

 joint smaller than preceding joint; joints 3-8 with slender basal spines 

 and row of short haus distally on lateral margin; bristles on joints 3-8 

 with natatory hau-s; end joint (fig. 10a) with 4 long distal bristles with 

 natatory hau-s and 2 smaller mediodorsal bristles with sparse marginal 

 hairs. 



Brady and Norman (1896, p. 660) report only 3 bristles on the 1st 

 joint of the endopodite of the 2nd antenna; however, 6 bristles are 



