Entomostraca from the Scottish Si j as. 124 



now described, however, the structure of the elongated left 

 leg differs from that of any of the others known to me in the 

 proportional lengths of the various joints and in the peculiar 

 armature of the terminal one. The mutilated condition of the 

 only specimen observed prevents a more detailed account 

 being given, but the characters available are, taken together, 

 sufficient to distinguish this form from its confreres,- 



Amallophora claviger *, sp. n. 

 (PI. III. tigs. 1-11; PI. IV. figs. 13-17.) 



Cephalothorax moderately elongated ; forehead rounded ; 

 rostrum bifurcate, with moderately long tapering branches ; 

 abdomen composed of five segments, caudal rami vey short. 

 Length about 4*7 mm. (PI. III. fig. 1). 



Antennules rather longer than the cephalothorax, mode- 

 rately slender and composed of twenty-five joints ; first and 

 second joints somewhat dilated, the next four small, subequal, 

 the sixth to the twelfth more or less coalescent, thirteenth and 

 fourteenth small, the fifteenth to the nineteenth rather longer 

 than the preceding two joints or those that follow, as in the 

 formula, which shows approximately the proportional lengths 

 of the various joints : — 



Number of the joints 1 2 34 5 6789 10 1112 



Proportional leDgths of same . . 17 . 12 . 7 . 8 . 7 . 8 . 38 . 



13 14 15 16 17 18 19 20 21 22 23 24 25 

 9 . 9 . 14 . 15 . 16 . 15 . 15 . 12 . 9 . 8 . 11 . 11 . 6 ~ 



See also the drawing (PI. III. fig. 3). 



Antennae small, inner branch much shorter than the outer 

 (PI. III. fig. 4). 



Mandibles small, narrow, elongated, distal end somewhat 

 constricted, biting end obliquely truncated and armed with 

 small denticles; mandible-palp small (PI. III. fig, 5; PI. IV. 



First maxilliped small, furnished with a dense fascicle of 

 sensory filaments and a number of setaa as shown in the 

 drawing (PL III. fig. 6). Second maxillipeds also small, 

 elongated, and sparingly setiferous (PL III. fig. 7). 



The four pairs of swimming- feet are somewhat similar to 

 those in Xanthocalanus borealis, G. 0. Sars. The fifth pair 

 has also a general resemblance to those of the same species, 



* Claviger, carrying a club ; referring to the club-like form of the left 

 leg of fifth pair. 



