236 BULLETIN 82, UNITED STATES NATIONAL MUSEUM. 



The tentacles appear to be without calcareous deposits. 



Comanthina schlegelii. The lateral perisome of the pinnules is thickly beset 

 with very minute spicules, which are continued into the ambulacral lappets, where 

 they become larger and tend to form loose aggregations. 



The distal side of the tentacles contains a thin continuous line of minute 

 spicules. 



Comanthus pinguis, The perisome of the pinnules contains a few scattered, 

 mostly very small, spicules. 



I have not been able to detect spicules in the tentacles, which, however, are very 

 thick and opaque. 



Comanthus solaster. The lateral perisome of the pinnules is beset with scat- 

 tered spicules. 



No deposits were detected in the tentacles. 



Comanthus japonica. The lateral perisome of the pinnules is beset with 

 numerous scattered spicules varying, in different pinnules, from minute to fairly 

 large. 



There appear to be no calcareous deposits in the tentacles. 



Comanthus trichoptera. The perisome of the pinnules contains minute scat- 

 tered spicules. 



No spicules were found in the tentacles. 



Comanthus benhami. The lateral perisome of the pinnules is beset with 

 very small spicules. 



The tentacles contain a band of small spicules along their outer side. 



Comanthus wahlbergii. The perisome of the pinnules contains numerous 

 minute spicules. 



There are a few spicules in the tentacles. 



Comanthus samoana. The lateral perisome of the pinnules contains scattered 

 needle-like spicules, mostly at right angles to the pinnulars, which may, especially 

 in the distal part of the pinnules, extend into the marginal lappets. 



The tentacles contain a band of spicules along the distal side. 



Comanthus annulata. The perisome of the pinnules appears to be almost 

 or quite devoid of calcareous deposits. 

 There appear to be no spicules in the tentacles. 



Comanthus parvicirra. Small scattered spicules occur in the perisome of the 

 pinnules. 



There are a few small spicules in the tentacles. 



Family ZYGOMETRID^]. 



Zygometra microdiscus. There appear to be no deposits in the perisome of 

 the pinnules. 



In a specimen from Western Australia each ambulacral lappet contains a 

 thick and conspicuous narrow plate which runs downward and slightly proximally, 

 often tapering somewhat, to the border of the pinnulars. Though narrow, these 

 plates, of which there are four to a pinnular, are quite close together, so that they 



