102 



BULLETIN 82, UNITED STATES NATIONAL MUSEUM. 



the reduplications of that ossicle have the outer distal angles sharply cut away, and 

 the IBr 2 and all of its reduplications have the outer proximal angles similarly 

 truncated, so that numerous rhombic intersegmental pores are formed which pass 



185 



FIG. 185. SLEXDER-AEMED VABIETT OF COMATDLA PECTINATA, FROM SPECIMEN FROM SINGAPORE. 



from the exterior through the thick calcareous wall formed by the postradial series 

 to the disk. These pores are especially evident in the species of Thalassometridse, 

 in which the division series are composed of two elements, as in many species of 



