the British Pandalidse. 29 



P. propinquus and P. Bonnier i agree with P. Montagui in 



the 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 proceeds to describe this appendage as " carrying a 

 small thread-like ecphysis " or exopod in P. falcipes 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 J and by Boas§, in which two arthrobranchise 

 correspond to that appendage. 



The fourth British species — P. brevirostris of Rathke — has 

 been referred by Spence Bate || 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 the rostrum and do not extend 

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

 while the " stylocevite " 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 Pandalidge described by Spence Bate, in the absence of 

 arthrobranchise from all the perseopods. 



While certain of the existing genera of Pandalidge 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. brevirostris 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. 



f Op. cit. p. 669. 



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



§ " Decap. Slaegtskabsforhold," Vidensk. Selsk. Skr. (6) Naturv. og 

 Math. Afd. i. 2, p. 162. 



|| Chall. Rep. Macrura, p. 653. 



f In Spence Bate's definition of the 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. magnocuhcs (op. cit. 

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

 from which it springs. 



