] 20 DICHELASPIS WARWICKII. 



1. Dichelaspis Warwickii. PL II, figs. 6, 6 a, b. 



Octolasmts Warwickii. /. B, Gray. Annals of Philosophy, 

 vol. x, p. 100, 1825 ; Spicilegia Zoologica, t. vi, fig. 16, 1830. 



D. scutorum segmento basali duplo latiore quam seg- 

 mentum occludens : tergorum parte inferior e paulb latiore 

 quam occludens scutorum segmentum. 



Scuta, with the basal segment twice as wide as the 

 occludent segment; terga, with the lower part slightly 

 wider than the occludent segment of the scuta, 



Mandibles, generally with four teeth. 



Off Borneo, attached to a crab (Belcher) : China Sea. British Museum. 



General Appearance. — Capitulum much compressed, 

 elongated, with the valves not very close together, the 

 carina being separated by a rather wide space from the 

 scuta and terga. Valves variable in shape, very thin and 

 translucent, covered by thin membrane, which, over the 

 whole capitulum, is studded with minute blunt points. 



Scuta. — Segments without internal teeth or an internal 

 basal rim ; the occludent segment long, narrow, pointed, 

 not quite flat, sometimes slightly wider in the upper 

 part; about one third of its own length longer than 

 the basal segment; occludent margin slightly arched; 

 basal segment about twice as wide as the occludent seg- 

 ment, triangular, slightly convex ; in young specimens 

 (PL II, fig. 6 b), the carinal margin of the basal segment 

 is protuberant, and the occludent margin hollowed out ; in 

 old specimens the occludent margin of the basal segment 

 is straight, and the carinal margin much hollowed out. 

 In very young specimens the basal segment is very small 

 compared to the occludent. 



Terga, variable in shape ; flat, lower part wider than 

 the occludent segment of the scuta; occludent margin 



