A H. CLAEK : THE CRINOIDS OF THE INDIAN OCEAN. 



27 



PentametrocrinidcE. 

 The family Pentametrocrinidse is composed almost entirely of deep-water 

 species. Both Decametrocrinus and Pentametrocrinus range from Greenland to 

 the extreme south of the Indian Ocean, and thence from East Africa to the East 

 Indies and Japan, Decametrocrinus reaching the Meangis and Hawaiian Islands. 

 As a family the range in depth is from 103 to 1,800 fathoms but, while attaining 

 the same abyssal limit, Decametrocrinus does not occur above 361 fathoms. 



Atelecrinidce. 

 The Atelecrinidffi, in many ways the most interesting, is the least known of 

 any of the comatulid families. Four species are recognized, one from the west 

 tropical Atlantic, the others from the Philippine Islands, Fiji, and the Hawaiian 

 Islands, the last {A. conifer) being much the largest. The range in depth in the 

 East Indian region is from 552 to 809 fathoms. 



Pentacrinitid(B. 

 The family Pentacrinitids includes, in the East Indian region, 28 species, 

 distributed in 4 genera of which one, Metacrinus, contains 22. Collectively the 

 species range from southern Japan to Fiji and the Kermadec Islands, and west- 

 ward to the west coast of India, but all the species belonging to three genera, 25 

 in all, are found within the locality of maximum intensity for Intermediate 

 forms; the fourth genus is not found in this area at all, occurring eastward only 

 to the Malay Peninsula. In depth the East Indian species of Pentacrinitida^ 

 range from about 60 to 1,350 fathoms, occurring most abundantly between 200 

 and 600. Three of the four genera are confined to the East Indian region, but 

 Endoxocrinus occurs on both coasts of the mid-Atlantic. In the Caribbean Sea 

 another genus is found, Isocrinus, represented by three species one of which, /. 

 asteria, is a shaUow-water form occurring up to 5 fathoms or even less. Isocrinus 

 is abundantly represented as a fossil in various horizons, especially in Europe, 

 but none of the other genera are known except in the recent seas. One of the 

 most abundant, best known, and handsomest of the fossil crinoid groups is the 

 genus Penlacrinites which so far has not been discovered in the lecent seas. 



Apiocrinidce. 

 The family Apiocrinids, including many of the best known of the fossil 

 crinoids, is represented in the recent seas by two genera, each with a single speci.s ; 

 these are Carpenterocrinus rnollis from southern Japan, in 565 fathoms of water, 

 and Proisocrinus ruberrimus from the Philippine Islands, in 940 fathoms. 



Hyocrinidce. 

 The family Hyocrinidae includes five genera which collectively occur from the 

 Queen Charlotte Islands, off British Columbia, and the Philippine Islands to the 



