162 



STALK-EYED CRUSTACEA. 



one begins at the orbit and runs backward and then obliquely upward to the 

 hind border of the carapace. It is separated anteriorly from the base of the 

 external orbital spine by a deep but narrow groove. The inferior lateral 

 carina is continuous in front with the inferior (branchiostegal) spine of the 

 anterior margin of the carapace. It trends backward nearly parallel with 

 the superior lateral carina, and becomes obsolete a little way from the hind 

 margin of the carapace. A smaller carina runs close to the lower margin of 



the carapace. 



The firsts second, and sixth segments of the abdomen are not carinated. 

 The third, fourth, and fifth segments are carinated along the median dorsal 

 line. On the third segment the carina is broken into two moieties, the ante- 

 rior of which is fluted above and terminates in a sharp spine a little behind 

 the middle of the segment, while the posterior portion is rounded above and 

 ends in a spine on the posterior border of the segment. The carina on the 

 fourth and fifth segments is unbroken, and ends in a longer spine at the pos- 

 terior border of each of these segments. Thus there are four spines in the 



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median dorsal line of the abdomen, two on the third segment, one on the 

 fourth, and one on the fifth. 



The telson ends in a long, acute, median tooth, which is flanked by two 

 pairs of movable spines. Of these the distal exceed the median tooth in 

 length ; the proximal, on the contrary, arc very small and short. There 

 are, moreover, three pairs of spines on the dorsal surface of the telson. 



The basal segment of the antennule is furnished with a long external 

 spine (stylocerite) which reaches nearly to the end of the second segment of 

 the antennule. At the base of this spine, against the eye-stalk, is a rounded 



lobe. 



The antenna) are twice the length of the whole body, including the 

 rostrum. The antcnnal scale reaches nearly half way to the end of the 

 rostrum ; its external lateral tooth is situate some distance behind the front 

 extremity. 



The third maxillipeds bear a rudimentary exopod hardly a fifth as long 

 as the ischium. 



The carpus of the right leg of the second pair is composed often seg- 

 ments ; on the left leg of the same pair the carpus contains from twenty-two 

 to twenty-seven segments. 



Dimensions of a male : length from tip of rostrum to end of telson, 

 197 mm. ; length of rostrum, 70 mm, ; length of carapace, including rostrum, 



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