MONOGRAPH OF THE EXISTING CRINOIDS. 



291 



in the ontogeny of the abrupt acceleration in cirrus growth which originally gave 

 rise to it, many of its peculiarities, so that it has become difficult to differentiate 

 from the other cirrals, and the segments grade more or less imperceptibly from the 

 long proximal into the short distal type. 





D P IH ID 



FIG. 319. 



FIG. 350. 



FIG. 351 



H3JHIC 



Fio. 352. 



FIGS. 349-352. 349, A CIRRUS FROM A SPECIMEN or DECAMETRA MOLLIS FROM KVRBACIII VIEWED (o) DORSALLY AND (!>) LAT- 

 ERALLY. 350, A CIRRUS FROM A SPECIMEN OF COLOBOMETRA DISCOLOR FROM THE EASTERN PART OF THE BAY OF BENGAL 

 VIEWED (a) DORSALLY AND (i>) LATERALLY. 351, LATERAL VIEW OF A CIRRUS FROM A SPECIMEN OF PROMETRA OWSTONI FROM 



SOUTHERN JAPAN. 352, A CIRRUS FROM A SPECIMEN OF OUGOMETRA SERRIPINNA FROM SINGAPORE VIEWED (a) DORSALLY 



AND (&) LATERALLY. 



In those oligophreate forms in which there is but little difference between tin- 

 proximal and distal segments, as in certain species of Amphimetra (figs. 86, p. 141, 

 335, p. 283, and 336, p. 285), in Cenometra (figs. 87, p. 143, and 345, p. 289), in Comac- 

 tinia echinoptera (fig. 328, p. 281), and in numerous species among the Himero- 



