no S. T. Smith — Crustaceans of the Atlantic Coast. 



pairs of spines. The basal poi'tions of the uropods are about a fourth 

 longer than the telson, slender, and each armed along the distal three- 

 fourths of the inner side with a series of ten to twelve small spines 

 which become more scattered proximally and never extend to the base. 

 The inner ramus is about two-thirds as long as the base, composed of 

 two segments, slender, tapers to a long and slender spiniform tip, and 

 is armed along the inner edge with eight to ten spines, of which four 

 are usually upon the basal segment, and one, or sometimes two, upon 

 the outer edge. The outer ramus is somewhat longer than the inner, 

 slender, tipped with two long setiform spines, and armed upon the 

 outer edge with six to ten very slender spines, but with only a single 

 spine upon the inner margin near the tip. 



The adult male ditlers from the female in being more slender, in 

 having the cephalothorax much more compressed vertically, and, 

 as usual in the genus, in the structure of the antennsB, the anterior 

 abdominal appendages, etc. The carapax is much more depressed 

 than in the female, the height being less than half the length, and 

 much broader and more obtuse anteriorly as seen from above. The 

 surface is more conspicuously pimctated than in the female, but the 

 anterior portion is areolated in the same manner, except that there is 

 in addition a prominent longitudinal carina-like crest each side, ex- 

 tending in a straight line from the inferior margin just in front of the 

 postero-lateral angle to the sharp curve at the lower end of the 

 second vertical crest. The margin of the carapax below this is in- 

 curved much more abruptly than in the female, so that the sides of 

 the carapax are angulated each side at the widest part, — almost 

 exactly as in the male of B. Rathkii. The telson is much longer 

 than in the female, has the usual sharp dorsal angle between the 

 basal and terminal portion, and is armed with eight to ten pairs of 

 slender spines which aj-e longer than in the female. The bases of the 

 uropods are armed with ten to sixteen spines, and the inner edge of 

 the inner ramus with twenty-four to thirty spines, of which ten to 

 twelve are on the basal segment. 



This is a much larger species than U. scidpttis, the length of the 

 adult female, from tip of rostrum to extremity of telson, being about 

 12'""'; of adult male, about 14"'"\ 



In life the males, at least, are semi-translucent, whitish, with the 

 ophthalmic lobe pink. 



Vineyard Sound!, July 20, 1875,--one young male taken at the 

 surface. Adult males were taken at the surface at the same locality, 

 bv Mr. Vinal :N. Edwards, December S, 1S75, March 22, 1876, April, 



^ 35-05.? asa^- 



