MONOGRAPH OF THE EXISTING CRINOIDS. 



237 



centrodorsal in the Oomasteridae and in other comatulids are of no little importance, 

 for there lie hi them the five rays of the basal star, which is in close connection with 

 the dorsal surface of the radial pentagon. As a general rule these intcrradial ele- 



FlG. 1911 



FIG. 192. 



FIG. 194. 



FIG. 196. 



FIG. 195. 



FIG. 19S. 



FIG. 197. 



Fios. 191-198. 191, DORSAL VIEW OF TUE CENTRODORSAL OF A SPECIMEN OF STENOMETRA DORSATA FROM SOUTHERN JAPAN. 



192, LATERAL VIEW OF THE CENTRODORSAL AND RADIALS OF A SPECIMEN OF STENOMETRA DORSATA FROM SOUTHERN JAPAN. 



193, DORSAL VIEW OF THE CENTRODORSAL OF A SPECIMEN OF STYLOMETRA SPINIFERA FROM CUBA. 191, LATERAL VIEW OP 

 THE CENTRODORSAL, BASAL RATS AND RADIALS OF A SPECIMEN OF STYLOMETRA SPINIFERA FROM CUBA. 195, DnKS.U. VIEW 

 OF TIIE CENTRODORSAL OF A SPECIMEN OF TlLiLASSOMETRA HAWAHENSIS FBOM THE IlAWAILVN ISLANDS. 196, LATERAL VIEW 

 OF THE CENTRODORSAL OF A SPECIMEN OF THALASSOMETRA UAWAEENSIS FROM THE HAWAIIAN ISLANDS. 197, DORSAL VIEW 

 OF THE CENTRODORSAL OF A SPECIMEN OF THALASSOIIETRA VILLOSA FROM THE WESTERN ALEUTIAN ISLANDS. 198, LATERAL 

 VIEW OF THE CENTRODORSAL OF A SPECIMEN OF THALASSOMETRA VILLOSA FROM THE WESTERN ALEUTIAN ISLANDS. 



vations and interradial grooves are, like the rays of the basal star/ entirely devoid 

 of pigment, which is, however, very abundant in the organic base of the calcareous 

 reticulation composing the rest of the ventral surface of the plate, so that when 



