110 Mr. W. Thompson on new species of British Crustacea. 



I would therefore now submit to malacologists, as I have 

 shown that no existing genus can with propriety receive this 

 curious creature, that a new one be constituted for it, and en- 

 titled Barleeia, as a just recollection of the exertions of a gen- 

 tleman who loses no opportunity of enriching science with living 

 objects from the Great Book of Nature ; and though the present 

 animal is locally common, it is malacologically an almost unre- 

 corded rarity. We may all blush for our carelessness in not no- 

 ticing this interesting and unique species, which, though within 

 the range of many naturalists, would still probably have remained 

 in obscurity if it had not been deterre and forced into notice by 

 our invaluable friend. 



I am, Gentlemen, 



Your most obedient servant, 



William Clark. 



P.S. — Errata in the paper on the genus Ti-uncatella in the last 

 July ' Annals :' — vol. xii. p. 7. line 24, for branchial, read oesopha- 

 geal streamlets. And ibid, p. 6, for Delia Chiaje, read Delle 

 Chiaje. 



XII. — Description of several new species of British Crustacea. 

 By William Thompson, Esq. 



[With a Plate.] 



HippoLYTE Whitei (mihi). White's Hippolyte. PI. VI. fig. 1. 



Spec. Char. Rostrum (fig. 1 a) straight, without spines above, 

 and slightly bifid at the apex, beneath with a sharp two-toothed 

 carina, and a minute one near the apex ; internal antennae with 

 the thick filament much-curved. 



The carapace of this species is more gracile than any other of 

 the genus, and even more slender than in the genus Pala^mon ; 

 it is terminated by a straight and elongated rostrum, without 

 any spine on its upper side ; the apex is rather blunt ; beneath 

 there is a short carina, which is deepish, and has two teeth* 

 there is besides a very miniite tooth close to the apex, whicti 

 gives the apex the appearance of being bifid ; it is, however, not 

 the case, the apex being quite distinct from the spine, which is 

 placed on the lower edge of the rostrum ; there is also a small 

 tooth on each side of the base of the rostrum, just over the 

 inner edge of the orbit, and another spine on each side the 

 carapace in a line underneath the antennse. The scale of the 

 external antennse is large, longer than the rostrum ; its external 



