MONOGRAPH OF THE EXISTING CBINOIDS. 



233 



The inner surface is studded with small opening;s which are the inner ends of 

 canals leading from the inner cavity to the centers of the cirrus sockets exteriorly, 



Fig. 182. 



FiQS. 181-182.— 181, Dorsal VIEW of the youngest sfecimen ofCouatul.i kotalaria obtaked by the "Challengeb," 



SHOWINO the functional CIKKI (after 1>. n. CARPE.NTEtt). 182, DoES.U. \1EW OF A SPECIMEN OF CoM.VNTHCS FAnVICIRBA, 

 SHOWING CIRRI PRESENT IN ONLY TWO OF THE LNTERRADLIL ANGLES OF THE CENTRODORS.U. (AFTER V. H. CARPENTER). 



and are contmued into the cirri (figs. 66-68, p. 93). In Antedon hifda these canals 

 average, according to W. B. Carpenter, 3^ inch in diameter, but they are pro- 

 portionallv larger in species having larger cirri. Most common^ the walls of this 



79140°— Bull. 82—15 16 



