P^ECILASMA AURANTIA. 105 



Size. — Capitulum in largest specimens half an inch 



long. 



2. PtECILASMA AURANTIA. PL II, Fig. 2. 



P. valvis 5 ; carina basi truncate! : scutis ovatis, 

 margine basali perbrevi, dentibus parvis, intemis, umbo- 

 nalibus instructo : tergorum acumine basati peroblique 

 truncato. 



Valves 5 ; carina with a truncated base ; scuta oval, 

 with the basal margin very short, furnished with small 

 internal umbonal teeth ; terga, with the basal point very 

 obliquely truncated. 



Maxillae with fine spines in the notch under the three 

 great upper spines; caudal appendages with scattered 

 bristles on their summits, and along only the upper part 

 of their outer margins. 



Madeira; found by the "Rev. R. T. Lowe, attached to the rare Homola 

 Cuvierii, probably a deep-water crab. British Museum. 



General Appearance. — This species so closely resembles 

 P. Kcempferi, that it is superfluous to describe it in 

 detail ; and I will indicate only the points of difference. 

 When the valves have been well preserved, they are of 

 fine pale orange colour, and hence the name above given, 

 which was proposed by the Rev. R. T. Lowe. 



Scuta, with the internal umbonal teeth small; basal 

 internal marginal rim very prominent, furrowed within ; 

 basal margin short, (only equalling half the length of 

 terga), owing to the great curvature of the lower part of 

 the carino-tergal margin ; hence, the outline of the scuta 

 is almost pointed oval. I saw no appearance of ine- 

 quality in the two sides. 



Terga, rather smaller in proportion to the scuta, than in 

 P. Kcempferi, with the basal end very obliquely truncated, 

 so as to appear at first simply pointed, not parallel to the 

 occludent margin ; apex considerably more pointed and 

 produced than in the foregoing species. 



