the British Pandalldte. 29 



P. propinqnus and P. Bonnieri agree with P. Montagui in 

 tlie essential characters of the genus Pandalus as defined by 

 Spence Bate *. That author, indeed, includes amongst these 

 characters the absence of an exopod from the third maxilliped ; 

 but as he ])rocceds to describe this appendage as " carrying' a 

 small thread-like ecphysis " or exopod in P. /a/c//;gs f, it is 

 plain that little importance can be attached to this point. 

 The branchial formula given by Spence Bate for this genus 

 is in error in attributing only one arthrobranchia to the third 

 maxilliped. In our species the formula agrees with that 

 given by Smith \ and by Boas§, in which two arthrobranchije 

 correspond to that appendage. 



I'lie fourth British species — P. hrevirostris oi Rathke — has 

 been referred by Spence Bate |i to his genus Nothocaris^ with 

 which it agrees in the possession of fixed " teeth " as well as 

 articulated " spines " in the dorsal armature of the carapace and 

 rostrum. It differs from that genus, however, in the fact 

 that the teeth are confined to th.e rostrum and do not extend 

 to the dorsal crest, which is furnished with spinules only, 

 while the " styloceiite " or basal scale of the antennule is 

 rounded as in Pandalus ^, not produced and pointed as in 

 Nothocaris. I find, moreover, that the branchial system of 

 this species differs from that of Nothocaris^ and, indeed, of all 

 the Pandalidte described by Spence Bate, in the absence of 

 arthrobranchiffi from all the perceopods. 



While certain of the existing genera of Pandalidte appear 

 to be by no means satisfactorily defined and a revision of the 

 whole group is much required, the very aberrant branchial 

 formula of P. hrevirostris may perhaps be held to justify the 

 creation of a new genus, for which I propose the name 

 Pandalina, for the reception of that species. 



Genus Pandalus, Leach. 



Carapace without lateral crests. Dorsal crest and upper 

 edge of rostrum armed with movable spinules only. Basal 



* Chall. Rep. Macrura, pp. 625 and 665. 



t Op. cit. p. 669. 



\ Bull. Mus. Comp. Zool. x. 1882-83, p. 66. 



§ " Decap. Slsegtskabsforhold," Vidensk. Selsk. Skr. (6) Naturv. off 

 Math. Aid. i. 2, p. 162. 



(I Chall. Rep. Macrura, p. 653, 



51 In Spence Bate's definition of tlie genus Pandalus the " stylocerite " 

 is said to be rounded and "but half the length of the joint which carries 

 it." Nevertheless he figures this structure in his P. magmculus {op. cit. 

 pi. cxv. fig. 1 b) as pointed and about two thirds the length of the joint 

 from which it springs. 



