CLARK: DISTRIBUTION OF UNSTALKED CRINOIDS 



213 



ZOOLOGY. — The hathymetrical and thermal distributidn of the 

 unstalked criniods, or comatulids, occurring on the coasts 

 of China and Japan. Austin H. Clark, National Museum.^ 



The fauna of the coasts of China and Japan includes 92 recog- 

 nized species and subspecies of comatulids, of which 2 are prob- 

 ably best considered as local aberrant forms, so that the actual 

 number may be placed at 90. 



Of these 90, 61 belong to the Indo-Pacific fauna, characteriz- 

 ing the Southern Japanese division of that fauna, which ranges 

 from Hong Kong and Formosa to the Korean Straits and thence 

 eastward to Tokyo Bay; 22 are Malayan, wide ranging types, 

 each with a distribution different from that of the others; 4 are 

 Antarctic, reaching Japan from the northeastward by way of 

 Alaska and the Aleu- 



O 16 c4 0.:. 4U 



tian Islands; and 3 

 (plus varieties of one 

 of them — 5 in all) are 

 Arctic. One of these 

 last, Heliometra gla- 

 cialis maxima (with 

 Heliometra glacialis 

 biarticulata and Helio- 

 metra glacialis hrachy- 

 mera) is very closely 

 related to Heliometra 

 glacialis glacialis, _ i a., ^ . j-a- + , +. r 



. Fig. 1. Ihe frequency at different depths oi 



which occurs m the ^j^g comatulids of the coasts of China and Japan. 



Arctic Ocean from The Species of the Indo-Pacific Fauna; 



west of Greenland to TheSpeciesof the Malayan Fauna; 



+ V. TT Q rl "^^^ Species of the Arctic and Antarctic Faunas; 



the Kara bea, and The Total for all Species. 



southward to Nova 



Scotia and northern Norway, but the other two are of quite 

 different origin; Psathyrometra erythrizon was originally Antarc- 

 tic, like Psathyrometra fragilis, to which it is closely related, and 

 entered the Seas of Okhotsk and Japan from the northeastward ; 

 Thau7natometra tenuis is most closely related to species in the 



' Published by the permission of the Secretary of the Smithsonian Institution. 



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