A MONOGRAPH OF THE EXISTING CRINOIDS 289 



Investigator; Arrakan coast, Burma [A. H. Clark, 1912] (3, U.S.N.M., 35077, 

 35194, 35212). 



Near Deli, northern Sumatra (lat. 3° 40' N., long. 99° 10' E.); 16-18 meters; 

 June 25, 1908 [A. H. Clark, 1933] (2, Buitenzorg Mus.). 



Dr. Th. Mortensen's Pacific expedition, 1914-16; off Jolo, Philippines; about 27 

 meters; March 21, 1914 (1, C. M.). 



Geographical range. — From the Philippines to the coast of Burma. 



Bathymetrical range. — From 27 to 73 (?89) meters. 



History. — This species was first mentioned in July 1912, when two small and 

 broken specimens were recorded from the Arrakan coast of Burma. It was formally 

 described in November of the same year from a single specimen dredged by the 

 Investigator at station 387. 



In 1933 I recorded two additional specimens in the Buitenzorg Museum from 

 near Deli, Sumatra. 



HETEROMETRA GRAVIERI A. H. Clark 



Heteromelra gravicri A. H. Clark, Proc. U. S. Nat. Mus., vol. 40, 1911, p. 8 (southeastern Africa), 

 p. 25 (description; Zanzibar); Bull. Mus. Hist. Nat., Paris, 1911, No. 4, p. 251 (detailed descrip- 

 tion; Zanzibar); Crinoids of the Indian Ocean, 1912, p. 127 (synonymy; habitat); Unstalked 

 crinoids of the >S'i6oga-Exped., 1918, p. 78 (in key; range). — Gislj£n, Kungl. Fysiogr. Sallsk. 

 Handl., new ser., vol. 45, No. 11, 1934, pp. 22, 48.— A. H. Clark, John Murray Exped. 1933-34, 

 Sci. Reports, vol. 4, No. 4, 1936, p. 100 (range), p. 104. 



Diagnostic features. — The brachials are distinctly wedge-shaped with the ends 

 never quite parallel and are not exceedingly short. The enlarged lower pinnules 

 are smooth, with the earlier segments keeled. The cirri are 21 mm. long with 36-39 

 segments of which the longest are from one-third to one-half again as long as broad 

 and those in the distal half are about twice as broad as long and bear short dorsal 

 spines. The 19 arms are 80 mm. long. P 2 is the longest pinnule and is composed 

 of 24 segments. P 3 is slightly smaller than P 2 , but much larger than P,. P 4 is about 

 as large as Pi. 



Description. — The cirri are XXVIII, 36-39, 21 mm. long, more slender than 

 those of H. joubini. The first segment is short and the following gradually increase 

 in length to the fifth or sixth, which is from one-third to one-half again as long as 

 broad, and after the eighth or ninth begin to decrease again so that those in the 

 distal half of the cirri are about twice as broad as long. The segments in the outer 

 half of the cirri bear short dorsal spines. 



Nine IIBr series of 4(3+4) are present. The division series have produced lateral 

 borders. 



The 19 arms in the type specimen are 80 mm. long. The brachials are only very 

 slightly overlapping. The arm structure resembles that of H. joubini. 



Pi is small and weak. P 2 is half again as long as P,, slender, and flagellate 

 distally, with 24 segments of which the second-fifth are carinate. P 3 is slightly 

 smaller than P 2 but much larger than Pj. P 4 is about as large as P,. The following 

 pinnules are slightly shorter than P 4 . The basal segments of all the lower pinnules 

 are distinctly carinate. 



Remarks. — Though of the same size as H. joubini, this species is as a whole more 

 slender and delicate. 



