Crustacea. 255 



ECHINOZONE SriNOSA. 



(Pis. XXXVIII. and XXXIX.) 



Specific character. Four prominent spines on each of the four 

 anterior thoracic segments, two on the cephalon ; smaller spines on 

 the epimera and on the posterior thoracic segments. 



Body ovoid, truncate in front but pointed behind, divided into 

 two by a deep constriction between the fourth and fifth thoracic 

 segments. Body arched and epimera well developed, both spinose. 



Cephalon arched in front, with two prominent spines situated 

 laterally ; the epimera are large and angular, with a small spine at 

 the antero-lateral angle and another about the middle of the plate. 



Thorax. First segment narrow with the epimera poorly deve- 

 loped ; the four large spines are confined to the body portion. The 

 three succeeding segments are similar, but the hinder margin of the 

 epimera are more rounded, passing backwards. Each segment has 

 the four prominent spines and a small one at the antero-lateral angle 

 of the epimera, the first two segments having an additional one 

 just behind this. The three posterior segments and the pleon taper 

 uniformly to a blunt point. The thoracic segments bear a spine on 

 either side the middle line, but on the last segment they are mere 

 rudiments. Of the first of these three segments there are four small 

 spines along the anterior margin. 



Fii'St antenna. Peduncle two-jointed. First joint large and 

 stout, with long seta on the margin and a spine at the distal 

 extremity. Second joint is very small proportionately, and bears 

 the multiarticulate flagellum. 



Second antenna. Five joints are visible from the dorsal surface. 

 The first of these bears a stout spine externally, the two distal joints 

 are very long, particularly the last one ; both are setose. The multi- 

 articulate flagellum is about half the length of the entire organ. 



Mandible. Anterior margin rounded to the cutting edge, which 

 is represented by a large blunt tooth ; a tuft of small setae lies close 

 below it, and the molar process is a long slender appendage setose at 

 its extremity. 



First maxilla. Outer lobe comparatively broad, curved. The 

 oblique terminal margin with a series of stout spines, of which 

 the two most distally situated are the longest. 



Second maxilla. Inner lobe broad, somewhat curved backwards. 

 One very long seta at the terminal angles. Outer lobe and palp 

 normal but stout. 



