526 On Two Species of the Genus Pandalus. 



The Museum collection includes a large number of speci- 

 mens of this species from various localities off the east and 

 west coasts of Ireland and the west of Scotland. 



Pandalus leptocerus, S. I. Smith. 



Pandalus leptocerus, S. I. Smith, Proc. U.S. Nat. Mus. iii. p. 437 (1881) ; 



Bull. Mus. Conip. Zool. Harvard, x. p. 58 (1882) ; Rep. U.S. Coinra. 



Fish, for 1882, p. 367, pi. v. fig. 1 (1884) ; A. Milne-Edwards, 



Recueil d;3 Figures de CrustacSs nouveaux ou peu connus, pi. xxii. 



(1883) ; Mary J. Rathbun, Harriman Alaska Exped. x. p. 43 (1901). 

 Pandalus falcipes, Spence Bate, Rep. 'Challenger' Macrura, p. 6(38, 



pi. cxv. fig. 2 (1888). 



Closely resembling P. bonnieri, from which it differs in 

 the following characters : — 



" The entire surface of the carapax and abdomen is slightly 

 roughened with short and irregular transverse punctate ridges 

 which give rise to very short bristle-like hairs." This 

 sentence, quoted from S. I. Smith, applies accurately to all 

 the specimens I have seen. On most parts of the surface the 

 ridges assume a crescentic form, giving the appearance of 

 imbricating scales, and they are quite easily seen even when, 

 as is often the case, the hairs have been rubbed off. 



Pandalus leptocerus, S. I. Smith. Proximal part of rostrum (above) 

 and basal segment of antennule (below). 



The interval separating the first two spines of the rostral 

 crest is commonly greater than that separating the second 

 and third ; only in one specimen was it seen to be slightly 

 less. As a rule, the third spine is in front of the orbital notch, 

 but in a few specimens it is almost directly above it. 



The proximal tooth on the lower edge of the rostrum is 



