Type-specimens of Poecilasma cavinatum. 



405 



with the chord of the occludeut margin is always very obtuse. 

 The convexity of the occludent margin varies considerably, 

 as shown in the figures, and so also does the curvature of the 

 carinal margin. The median ridge of the carina stops a little 

 short of the base, forming a tooth which is most prominent 

 in the smallest specimens. 



Fig. 3. 



Megalasma {Glyptelasma) carinatum (Hoek). Specimen from coast of 

 Cuba. Body, from the side, to show dorsal filamentary ap- 

 pendages, first cirrus, and caudal appendages. 



In the specimen figured by Gruvel the outline of the 

 scutum differs only very slightly from that of the holotype ; 

 Gruvel's figures represent rather too sharp an angle between 

 the basal and occludent margins. The other specimens from 

 the same locality show considerable variation in this respect ; 



