Chilton.— <-The New Zealand Species of Elasmopus. 



325 



Mandible with third joint of palp slender, its liind margin straight, 

 front margin sparsely setose, not pectinate. First gnathopoda setose ; 

 ischium ending acutely ; carpus not much shorter than propod, with nume 

 rous tufts of slender setae on its inferior margin and lower surface ; propod 

 oblong with palm slightly oblique, inner surface bearing a well-marked 

 oblique comb-like row of short stout setae increasing in length towards the 

 distal end of the row and numerous transverse rows or tufts on the hind 

 margin and adjoining inner surface, also three similar transverse rows on 

 the distal half of the anterior border, the third being at the base of the 

 dactyl. Second gnathopoda similar in general form to the first, but larger; 

 carpus longer than broad, fully half as long as the propod, both with 

 numerous tufts of setae arranged on the whole as in the first gnathopod but 

 without the charactertistic comb-like row on the inner surface of the propod. 



Peraeopoda rather stout, basal joint rounded-oblong and well expanded, 

 posterior margin simply serrate. Telson about as long as peduncle of third 

 uropod, each lobe bearing three or four long setae at extremity and having 

 the outer angle acutely produced. 



Male differing from female in the second gnatho- 

 poda and the peraeopoda. The peraeopoda, espe- 

 cially the fifth, are stouter and more setose, but 

 the posterior margin of the basal joints is only 

 slightly serrate with long flat serrations ; merus, 

 carpus, and propod broadened and densely setose. 



In the gnathopoda there are two forms. In form 1 

 the basal and ischial joints have the outer margins 

 produced into a thin flat flange, especially at the 

 distal end. and the anterior surface hollowed to 

 received the greatly enlarged propod when it is bent 

 back on them ; ischium produced distally into an 

 acute point ; carpus very short, cup-shaped, its 

 posterior border forming a densely setose lobe ; 

 propod very large, broader than the carpus, fringed 

 behind with long slender setae partially arranged in 



Fig. 5. — Elasmopus subcarinatus, male, form 2. Second gnathopod. 

 Fig. 6. — Elasmopus subcarinatus. Fifth peraeopod. 



transverse rows, palm in fully developed individuals with a broad spinulose 

 process near the finger-hinge followed by a deep cavity, a strong tooth, a 

 feeble oblique emargination, and a defining denticle ; dactyl stout, strongly 

 bent, minutely dentate near the base, with a large triangular process 

 opposite the central palmar tooth, apex subacute reaching the palmar denticle. 



