100 



THE FAUNA OF THE DEEP SEA 



FIG. \l.Rhizo- 

 crinus lofotensis, 

 one of the deep- 

 sea stalked Cri- 

 noids. (After 

 Carpenter.) 



chiefly found at depths of more 

 than 200 fathoms, a few only 

 extending into 140 and even 

 70 fathoms. 



There are six genera known, 

 and of these, two, Hyocrinus 

 and Bathycrinus, are not found 

 in less than 1,000 fathoms of 

 water. 



There can be no doubt that 

 these modern stalked Crinoids 

 are closely related to many of 

 those that flourished in bygone 

 periods of the history of the 

 earth. As Carpenter has 

 pointed out, the family Pen- 

 tacrinidas are remarkable for 

 their long geological history. 

 The genus Pentacrinus itself 

 first appeared in the Trias and 

 persisted through the Secondary 

 and Tertiary times to the pre- 

 sent day. 



The general character of 

 the fossil Pentacrinidas is es- 



