1885.] PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 181 



pax excluding the rostrum, fully a third as broad as long:, the inner 

 margin broadly curved distally, and the tip rounded. The flagellum is 

 very nearly naked and three or four times as long as the rest of the 

 animal. 



The second gnathopods are slender, regularly tapered, and reach 

 to about the tips of the antenna! scales ; the ischium and carpus are 

 approximately equal in length and a little longer than the merus, 

 which is slightly longer than the propodus, which in turn is longer 

 than the dactylus. 



The first perjeopods reach to or a little by the middle of the carpi 

 of the second gnathopods and are somewhat compressed : the basis 

 and ischium are each armed with a small distal spine and there is a 

 similar spine on the middle of the merus; the carpus and merus are 

 approximately equal in length, and the chela is about two-thirds as 

 long as the carpus. The remaiaing perceopods are unarmed. The sec- 

 ond reach by the middle of the antennal scales : the merus is shorter 

 than the carpus and subcylindrical ; the carpus is twice as long as in 

 the first and tapered distally ; the chela is approximately as long as 

 in the first, but much more slender and a little more than a third as 

 long as the carpus. The third reach to about the tips of the antennal 

 scales and are similar to the second, though the carpus is propor- 

 tionally still longer. The fourth reach to about the middle of the an- 

 tennal scales : the merus and carpus are approximately equal in length, 

 but the carpus is much the more slender; the propodus is less than 

 half as long as the carpus ; and the dactylus is about three-fifths as 

 long as the propodus, strongly compressed, with the edges sharji and 

 a longitudinal carina on the middle of each surface. The fifth are 

 similar to the fourth, but more slender, and reach to about the tips 

 of the antennal scales; the propodi are proportionally longer than 

 in the fifth, and the dactyli actually shorter, being less than a third 

 as long as the propodi. 



The dorsum of the second somite of the pleoii is broad and rounded, 

 but with a low and indistinct median carina, which becomes distinct 

 on the third somite and sharp and high upon the compressed fourth, 

 fifth, and sixth somites, and ends in a small tooth on the posterior 

 margin of the sixth. The postero-inferior angles of the first and sec- 

 ond pleura are rounded, while those of the third, fourth, and fifth are 

 obtusely right-angled. The sixth somite is between a fourth and a 

 third longer than the fifth, and rather more than three-fourths as high 

 as long. 



Thetelson is once and two-thirds to once and three-fourths as long 

 as the sixth somite, regularly tapered, with a very shallow dorsal sulcus 

 margined with slight carinse which terminate in a pair of small spiui- 

 form lateral processes a little way from the acutely triangular tip. 



The inner lamella of the uropod is about as long as the telsou and 

 nearly or quite three times as long as broad. The outer lamella is 



