234 BULLETIN 82, UNITED STATES NATIONAL, MUSEUM. 



The tentacles contain a conspicuous and continuous layer of spicules along 

 their outer side, which reaches nearly to the tips. 



Comaster minimus. — ^There appear to be no calcareous depsits in the ventral 

 perisome of the pinnules. 



There appear to be few or no spicules in the tentacles. 



Comaster multibrachiata. — The ambulacral lappets may contain very small 

 plates, with unfinished edges, composed of from 6 to 12 meshes, which may be 

 roimded or more or less irregularly elongated toward the pinnulars; but usually 

 perisomic deposits appear to be absent. 



The perisome of the nontentacular pinnules contains numerous small rounded 

 plates, and quantities of minute rods and spicules. 



The tentacles contain a very conspicuous layer of spicules, which are at first 

 branched, later becoming simple and distally minute, which continues along the 

 outer side nearly to the tips. 



CoTnaster fruticosus. — The lateral perisome of the pinnules contains irregular 

 rods at right angles to the pinnulars, three to each, or is quite without deposits. 



The tentacles contain a continuous layer of small spicules which at first are 

 branched, later becoming simple and distally very minute, which extends along 

 their outer side nearly to the tips ; on account of the almost or quite complete absence 

 of other deposits these tentacular deposits are very conspicuous. 



Comaster distincta. — ^There appear to be no deposits in the lateral and ventral 

 perisome of the pinnules. 

 - The genital glands are completely covered by large thin filmy plates. 



The tentacles contain a continuous layer of spicules, at first branched, later 

 becoming simple, and then minute, which reaches nearly to their tips. 



Comaster parvus. — The lateral perisome of the pinnules contains small and 

 widely scattered spicules. 



The tentacles contain a continuous layer of spicules, which runs along their 

 outer sides nearly to their tips. 



Comaster taviana. — Beyond a few widely scattered and inconspicuous spicules 

 along the borders of the pinnulars the perisome of the pinnules appears to be with- 

 out deposits. 



A continuous band of very small spicules runs along the outer side of the 

 tentacles almost to their tips. 



Comaster delicata. — On some pinnules the lateral perisome contains evenly 

 spaced spicules, usually standing at right angles to the pinnulars, but for the most 

 part the perisome is without calcareous deposits. 



On their outer side the tentacles contain a continuous layer of very small 

 spicules, which reaches nearly to their tips. 



Comantheria hriareus. — There appear to be no deposits in the ventral perisome 

 of the pinnules. 



A few of the tentacles, in the terminal pinnules and in the distal part of the 

 others, contain spicules near their bases. 



Comantheria polycnemis. — There appear to be no deposits in the ventral 

 perisome of the pinnules. 



