176 



Tribe CATAMETOPA. 



Family Gonoplacid.i:. 



Sub-family, Rhizopin^. 



Genus Ceratoplax, Stimpson. 



Ceratoplax punctata, n. sp. PI. xxiii., figs. 2, 2a, 2b. 



Body rather thick. 



The carapace is broader than long, very convex in the 

 antero-posterior direction, much less so in the transverse; 

 smooth, polished, and, except on the margins, glabrous with 

 scattered pits ; two of these, situated about the middle, and 

 rather distant apart, are more conspicuous, and below them is 

 a faint marking of a broad H in pits ; behind this, on each side 

 of the intestinal region, is a small area of wrinkles. 



The front is almost vertically depressed, less than one- 

 third the width of the carapace rounded at the external ends, 

 and medianly a little insinuate and slightly notched. The 

 antero-lateral margins are slig-htly cristate, obscurely lobed by 

 two or three faint notches, shorter than the postero-lateral 

 margins. Postero-lateral margins nearly parallel. Posterior 

 margin broadly arcuate and raised to a ridge. Except on the 

 posterior margin the carajpace has a dense fringe of long cilin. 

 which traverses the ocular peduncles ; beneath the fringe the 

 surface is more or less granulate. The orbits are moderately 

 large and excavated into the upper surface ; they are also 

 somewhat elongated. The ocular peduncles almost completely 

 fill them, and are levelled off to be nearly flush with the sub- 

 ocular surface ; the internal sub-ocular angle is not produced. 

 The eye is narrow and slit-like. 



The antennules which fold transversely are partially 

 hidden by the front. 



The basal joints of the antennae close the hiatuses of the 

 orbits and extend beyond the sub-ocular angles, but scarcely 

 reach the front; the second joints extend a little beyond the 

 front. 



The epistome is narrow — transverse. 



The sub-ocular and pterygostomial regions are slightly 

 concave or flat. 



The external maxillipeds are very hairy and almost close 

 the buccal orifice ; the ischium is slightly sulcated longitudi- 

 nally and iointed to the merus obliquely-straight. The merus 

 is sub-quadrate, with its internal distal angle not much trun- 

 cated, the distal margin slightly insinuated ; much produced 

 with a rounded lobe at the external distal angle, that portion 

 covering the end of the exopod. The succeeding joint is 

 articulated at the inner angle of the merus. The exopod is 

 broad. 



