MUSEUM OF COMPARATIVE ZOOLOGY. 45 



with tlie horizontal diameter about three fourths as great as the breadth of the 

 antennal scale and only a little less than the length of the eye to the base of 

 the stalk. In the alcoholic specimen, the pigment is deep purplish and is 

 probably not black in life. 



The peduncle of the antennula reaches to the tip of the antennal scale and 

 nearly to the tip of the rostrum, and is clothed along the sides and below with 

 very fine hairs, but is nearly naked above ; the first segment is a little longer 

 than the second and third together, the second nearly as long as the last, which 

 is less than twice as long as broad. The flagella are both nearly naked ; the 

 outer is about as long as the peduncle, the proximal two thirds of its length 

 vertically compressed and broad, but the terminal portion suddenly contracted ; 

 the inner is a little longer than the outer, very slender and regularly tapered. 



The antennal scale is regularly ovate, with the greatest breadth about two 

 thirds of the way from the tip to the base, where it is very much contracted at 

 the articulation ; both margins are thickly ciliated, and the tooth of the outer 

 margin is represented by an obscure angular projection at less than a third of 

 the way from the base to the tip. The narrowness of the articulation permits 

 great lateral motion in the scale, so that it may be turned outward at nearly a 

 right angle to the body. The segments of the peduncle are without spines or 

 tubercles ; the last segment is about as long as the breadth of the scale and 

 reaches three fourths of the way from its base to its tip, and the inner edge is 

 compressed and ciliated. The flagellum is a little longer than the carapax in- 

 cluding the rostrum, slender, compressed vertically, and almost naked. 



The tips of the external maxillipeds reach to about the tips of the antennal 

 scales. The proximal of the three segments of the endopod is about as long as 

 the antennal scale and five or six times as long as broad ; the second segment 

 is about two fifths as long as, and slightly broader than, the first, vertically 

 compressed, thickly ciliated along the inner edge, and armed beneath with a 

 single movably articulated spine near the distal end, and with two or three 

 similar spines along each edge ; the last segment is a little longer than the 

 second, flat and smooth above, tapers from the base to a slender -curved and 

 acute "tip, and the under surface and lateral margins are armed with thirteen or 

 fourteen movably articulated spines among which there are a few fascicles of 

 setae. The exopod is very slender,., the basal portion slic^htly longer than the 

 flagelliform portion, and the whole considerably shorter than the i>roximal seg- 

 ment of the endopod. 



The legs of the first pair are just about as long as and scarcely stouter than 

 the external maxillipeds, and reach a little beyond the bases of their dactyli, or 

 nearly to the tips of the peduncles of the antennae : the ischium is about as 

 long as the propodus, the inner and outer margins nearly parallel, the outer 

 articulating with the merus, while the inner is thin, nearly straight, closely ap- 

 proximated, and armed with a few seta;, and each projects forward bej'^ond the 

 articulation with the merus in a narrow dentiform prominence ; the merus is 

 as long as the three distal segments together, about a fourth as long as broad, 

 slightly compressed vertically and with a few setae along the inner edge, but 



