86 



Nematocarcinus, A. M. Echv. 



Tfematocarcinus, A. Miliip Edwards, Ann. Sci. Nnt., Zool., ((i| XI. 1881, Art. 4, p. 14. 

 BumierHa, S. I. Smitli, Bull. Mns. Cnmp. Zool. X. 1882-83, p. 77. (ipso t'ste). 

 Nematocarcinus and Stochasmus, Spenre Bute, Challenger Crust. Maorura, pp. 800, 822. 



Body modei'ately compressed. Rostrum long or moderate, dorsally serrated, 

 the teeth sometimes articulated. Carapace smooth, the anterior border with a 

 post-antennular and a true branchiostegal spine. 



Abdomen smooth, the 3rd tergum usually with a strongly convex posterior 

 border, the pleura thin and wide. Telson long, tapering, with well developed 

 spines at tip. 



Eyes large and well pigmented. Antennular peduncle short, the basal 

 joint dorsally concave for the eye and with a sharp scale at tbe base of the outer 

 border : the antennular flagella are of very great length, the outer one is a little 

 thickened at base. Antennal scale long and narrow, with truncate tip : the 

 outer margin broadly thickened, and ending in a little spine. 



Scaphognathite acutely produced posteriorly. External maxillipeds shorter 

 than any of the legs. 



The legs are remarkable for the enormous length of the ischium merus and 

 carpus — particularly of the carpus — and for the curious thickened and splice-like 

 articulation between the ischium and merus. The first 2 pairs end in small and 

 slender chela?, which are a good deal concealed by tufts of seta? : the 2nd pair 

 are a good deal longer than the 1st. The last 3 pairs, which are of nearly equal 

 length, are longer than the 2nd pair, and end in slender dactyli which are more 

 or less concealed in a brush of seta?. 



The abdominal appendages are all biramous : in the 2nd-5th pairs the 

 endopodite has the usual internal appendix at its base, the 2nd pair in the male 

 having an additional appendix. 



The last 3 thoracic sterna are strongly carinated fore-and-aft on either side 

 in the male, but in the female only the ante-penultimate sternum is distinctly so 

 carinated. 



The branchial formula is as follows : — 



Total 



1 + 7 ep. 



= 12 + 7 ep. 



