268 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



Comissia hartmeyeri A. H. Clark, Proc. U. S. Nat. Mus., vol. 43, 1912, p. 381 (cotype from Eig 

 [Erg] Tor, Gulf of Suez, in U.S.N.M.); p. 385 (identity of previous record); p. 386 (detailed 

 description; locality); Crinoids of the Indian Ocean, 1912, p. 314 (detailed description; Eig 

 [Erg] Tor).— Hartmeyer, Mitt. zool. Mus. Berlin, vol. 8, Heft 2, 1916, p. 233 (Erg Tor 

 No. 5601). — A. H. Clark, Unstalked Crinoids of the Siboga Exped., 1918, p. 20 (in key; range)' 



Diagnostic features. — The cirri are usually about X, 12-13, usually about 5 mm. 

 long; the longest cirrus segment is from three and one-half to four times as long as 

 the median width. The arms are slender, from 30 mm. to 39 mm. in length; the 

 brachials, which are relatively long, have strongly produced and overlapping spinous 

 distal ends. 



Description. — The centrodorsal is thin discoidal, with the dorsal pole flat, about 

 1 mm. in diameter. 



The ch-ri are VIII-XIV (usually about X), 10-13 (usually 12 or 13), from 4.5 

 mm. to 6 mm. (usually about 5 mm.) long. The first segment is short, the second 

 is about as long as broad, the third is from two to three times as long as its median 

 width, and the fourth is the longest, from three and one-half to four times as long as 

 the median width. The fifth segment is not quite so long as the fourth, and the 

 following segments rapidly decrease in length, so that the ninth and following are 

 about as long as broad. The fifth is a transition segment. The longer proximal 

 segments are oval in cross section and are strongly constricted centrally, but the 

 short distal segments have straight sides and are strongly compressed laterally, 

 appearing therefore broad in lateral view. The transition and following segments 

 have the distal dorsal edge everted, forming a minute sharp tubercle in lateral view 

 which is at first subterminal but becomes median on the antepenultimate. The 

 opposing spine is represented by a minute median tubercle which is only slightly 

 larger than the tubercle on the preceding segment. The terminal claw is slightly 

 longer than the penultimate segment, rather stout, and strongly curved, more so 

 basally than distally. 



The radials are even with the edge of the centrodorsal in the median line, but 

 extend upward interradially and entirely separate the bases of the IBr,. The IBr 

 series are widely separated, their sides making nearly a right angle with the sides of 

 the adjacent IBr series. The union of the elements of the IBr series is very close, 

 appearing almost like a syzygy in external view. 



The 10 slender arms are from 30 mm. to 39 mm. long. The brachials, which are 

 proportionately long, have strongly produced and overlapping spinous distal ends. 



The mouth is marginal and the anal tube subcentral. The anal area is completely 

 covered with small thin calcareous plates. 



Notes. — The type material consists of S specimens, 3 of which are now in the 

 National Museum. 



In the example which was selected as the type specimen the cirri are IX, 11-13, 

 5 mm. to 6 mm. long. The arms are 30 mm. long. Syzygies occur between brachials 

 3 + 4, 10+11, or 11 + 12 (usually the latter), and 14 + 15 to 17 + 18, and distally at 

 intervals of 3, more rarely 2, muscular articulations. 



Another specimen has the cirri VIII, 10, 4.5 mm. long. The arms are 33 mm. long. 



A third specimen has the cirri XIV, 11-12 (usually the latter), 5 mm. long, and 

 the arms 39 mm. long. 



