G. M. Thomson. — On new Crustaceans. 237 



posteriorly into a tooth, which makes the palm nearly transverse, sparingly 

 setose towards the extremity ; dactylos arcuate, nearly twice as long as the 

 palm. First and second pairs of pereiopoda rather short, simple, and 

 nearly destitute of spines or seta; ; third pair shortest of all, joints densely 

 fringed with long seta3, and the propodos strongly spined on its inferior 

 margin; fourth pair twice as long as third, dactylos directed backwards ; 

 fifth pair longer still, being nearly equal in length to the whole body, the 

 basa of these three last pairs are much dilated and setose on their margins. 

 Three posterior pairs of pleopoda ending subequally, ante-penultimate and 

 penultimate pairs with strong curved spines on their basal joints and rami; 

 ultimate pair very small and feebly developed, with a few seta?, but no 

 spines, internal ramus very minute. Telson short and rounded at its extre- 

 mity. Colour a dirty-grey, similar to that of the sandy-mud of the creek in 

 which it occurred. Length •§- inch. 



Hab. Brighton Creek (salt water), near Dunedin. 



This species is very distinct from any hitherto described, the form of the 



meros of the 2nd gnathopod being quite remarkable ; a tendency towards a 



similar development of structure occurs apparently in C. longicorne, which 



is, however, a very different species in many respects. 



Fam. OXYCEPHALIES. 



Genus Oxycephalies, Edw. 



Milne-Edwards, Ann. des Sc. Nat., t. xx., 1830, p. 396. 



C. Claus, Die Gattungen und Arten der Platysceliden, 1879, p. 44. 



Body elongated, slender, cephalon produced into a triangular beak, from 



the base of the under-surface of which the anterior antennae project. These 



have the peduncle greatly dilated in the male, and thickly furnished with 



olfactory seta? ; flagellum 2- or 3-jointed. The posterior antenna? are 5- 



jointed in the male, and lie behiud the snout under the inflated portion of 



the head, all the joints being folded close against one another ; in the female 



they are wanting. The mandibles are small, and furnished with a slender 



3-jointed palp in the male. The maxilla? are totally wanting. The maxil- 



lipedes are also greatly reduced in size, and their squamiform plates are 



smoothly rounded. The gnathopoda have complex chela?, the carpus being 



produced into a long narrow point, which meets the dactylos ; those of the 



first pair are shorter than the second. The first two pairs of pereiopoda 



have the joints very slender, in the third and fourth the basa are broadly 



dilated, while the fifth pair are very much smaller, but have all the joints 



present. The three posterior pairs of pleopoda are double-branched, the 



branches being broadly lanceolate. The triangular telson seems to be 



anchylosed to the preceding segment, 



