REPORT ON THE CRUSTACEA MACRURA. 



873 



Ophthalmopoda short and cylindrical. 



First pair of antennae biflagellate, and scarcely as long as the carapace. 



Second pair of antennas having a broad scaphocerite, armed with a tooth on the outer 

 distal extremity, and carrying a slender flagellum. 



Second pair of gnathopoda pediform. 



First pair of pereiopoda narrow, chelate ; second pair chelate and longer than the 

 first ; third pair about half the length of the second ; fourth pair about half the length 

 of the third, and feeble and slender ; fifth pair a little stouter and slightly longer 

 than the fourth, but not so long as the third ; all the pairs carry a broad and stout 

 basecphysis. 



Pleopoda moderate in size and biramose, excepting the first pair, which has the 

 inner branch resembling a small bud-like process ; all are attached to the lateral margin 

 of the coxal plates. Sixth pair long, narrow, and reaching beyond the extremity of the 

 telson ; inner branch lanceolate and fringed with hairs ; outer rounded, the external 

 margin being furnished with a strong tooth, and the inner fringed with hairs ; no evidence 

 of a diaeresis. 



Habitat.— Station 45, May 3, 1873 ; lat. 38° 34' N., long. 72° 10' W.; south-east of 

 New York; depth, 1240 fathoms ; bottom, blue mud; bottom temperature, 37° - 2. One 

 specimen. 



Dredged. 



This species corresponds much in general form with Pasiphsea tarda, Kroyer, 1 but 

 differs in the length of the flagella of the first pair of antennae, and in the more impor- 

 tant character of the development of the coxal plates of the somites of the pereion ; it 

 also has the propodos of the second pair of pereiopoda proportionately longer than 

 Kroyer's species. 



The carapace is less laterally compressed than in the more typical species of 

 Pasiphsea, and is distinguished by an elevated line that runs from the antennal tooth 

 to the posterior portion of the branchial wall, but does not reach the posterior margin. 

 The frontal margin projects to a small rostral point between the ophthalmopoda, it carries 

 no dorsal crest, but a very slight carina traverses the anterior portion in the median line. 



The somites of the pleon differ somewhat in length ; the first is the shortest and is 



1 Voy. en Scandinavie, Atlas, pi. vi. fig. la, 1846. 



(ZOOL. CHALL. EXP. PAKT LII. 1887.) Fff 110 



