810 BULLETIN 82, UNITED STATES NATIONAL MUSEUM VOLUME 1 



Thermal range. From 2.31 C. to 6.7 C. ; the average of 15 records is 4.6 C. 



Remarks. Off southern Japan the Albatross dredged Pentametrocrinus tuber- 

 culatus alone at station 3661 in 309 meters with a bottom temperature of 8.89 C. 

 This is evidently a shallow water form as it has been twice taken without elaborate 

 dredging equipment. 



Pentametrocrinus diomedeae alone was taken at station 4934 in from 188 to 279 

 meters with a temperature of 13.33 C. 



Pentametrocrinus japonicus alone was dredged at stations 4900, 4903, 4958, 4976, 

 4980, and 5079, in from 254 (?195) to 996 meters with temperatures from 3.72 C. to 

 11.61 C. 



Pentametrocrinus varians only was dredged at stations 3721, 4906, 4911, 4912, 



4915, and 4920 in from 714 (?378) to 804 meters with temperatures from 5.44 C. to 

 6.33 C. 



Pentametrocrinus varians in company with P. japonicus was dredged at stations 



4916, 4919, 4975, 5082, and 5083 in 660 to 1301 meters with temperatures from 3.05 C. 

 to 5.95 C. 



Pentametrocrinus japonicus and P. varians thus appear to occupy about the same 

 habitat so far as temperature and depth are concerned, although it is worthy of note 

 that P. japonicus was found at stations with lesser depths and higher temperatures 

 than P. varians. Wherever P. japonicus and P. varians were found together the ex- 

 amples of each were always of practically the same size; when P. varians was large and 

 robust, P. japonicus was also large and robust and when P. varians was small P. japon- 

 icus was also small, suggesting that the same factors influenced the growth of each in 

 the same degree. 



Pentametrocrinus japonicus can be distinguished at a glance from P. varians by 

 its more robust and massive appearance. In color the two species are practically the 

 same. 



At some places off the Japanese coast these comatulids were extraordinarily 

 abundant, coming up in hundreds in the net or on the tangles. It was only possible 

 to preserve a very small proportion of those collected. 



[NOTE BY A.M.C.] This species has been recorded a number of times by Mr. 

 Clark from various stations in the Indo-West Pacific. In 1923 Dr. H. L. Clark gave 

 the name varians to a specimen taken off South Africa after comparing it with others 

 from Japan. He does not mention the occurrence of the proximal pinnules. I think 

 this specimen is more likely to be P. atlanticus since a number of species occurring in 

 the northeast Atlantic are also found at the Cape, although sometimes the southern 

 forms have been distinguished as subspecies. 



PENTAMETROCRINUS, sp. 



Endiocrinus, sp. CHUN, Aus den Tiefen des Weltmeeres, 1900, p. 488. 



Pentametrocrinus, sp. A. H. CLARK, Proc. U.S. Nat. Mus., vol. 40, 1911, pp. 5, 49 (same record); 



Crinoids of the Indian Ocean, 1912, p. 288 (same record); John Murray Exped. 1933-34, Sci. 



Reports, vol. 4, No. 4, 1937, pp. 102, 104 (listed). 



Remarks. Professor Chun records the capture by the Valdivia of a sulphur- 

 yellow species of Pentametrocrinus, determined as a new species by Prof. Ludwig 

 Doderlein, off the coast of Somaliland, northeastern Africa, in 1289 meters. 



