312 HI I.LETIN 82, UNITED STATES NATIONAL MUSEUM 



The 14 arms of the type specimen are about 100 mm. in length. The first 

 brachials are very short, slightly wedge-shaped, almost entirely united interiorly. 

 The second brachials are larger, mure obliquely wedge-shaped. The first syzygial 

 pair (composed of brachials 3+4) is oblong, from two and one-half to three times as 

 broad as long. The next five or six brachials are oblong, three to four times as broad 

 as long, those succeeding becoming wedge-shaped, moderately oblique, about three 

 times as broad as long, soon gradually becoming less and less oblique, and in the outer 

 part of the arms being very short, three or three and one-half times as broad as long, 

 and only slightly wedge-shaped. 



P D is 11 mm. long, with 33 segments, moderately stout basally but tapering 

 rapidly and becoming very slender and flagellate in the distal half. The segments at 

 first are nearly three times as broad as long, but gradually increase in length and 

 become nearly or quite as long as broad in the distal third. Pi is 13 mm. long, con- 

 siderably stouter than P D and tapering much less rapidly, with 26 segments, of which 

 the second-eighth are strongly carinate. P 2 is 22 mm. long, similar in general to Pi 

 though much larger and stouter and tapering less rapidly, with 30 segments of which 

 the proximal are broad and those following become about as long as broad on the 

 tenth or twelfth and remain so until near the tip ; the second-fifth segments are strongly 

 carinate. P 3 is 13 mm. long, much smaller and slenderer than P 2 . P< is somewhat 

 smaller than P 3 . P 6 is 9 mm. long, somewhat smaller than P 4 ; the proximal carination 

 occurs on the second-sixth segments. The following pinnules very slowly become 

 slenderer, at the same time gradually increasing in length. The distal carination of 

 the proximal segments, which is very marked on the earlier pinnules, gradually be- 

 comes less and less marked, involving fewer and fewer segments; it is but slightly 

 evident beyond the twentieth. The distal pinnules are 10 mm. long. 



The color in alcohol is a uniform purplish or violet-black. 



Locality.— Red Sea; Hemprich and Ehrenberg [J. Miiller, 1841, 1843, 1849; 

 A 11. Clark, 1911, 1912, 1918] (1, Berl. M., 1055). 



History. — The single known specimen of this species was studied by Prof. Johannes 

 Miiller and is part of the material upon which he based his Alccto savignii described in 

 1841 and redescribed under the name of Comatula (Alecto) savignii in 1849. 



Later someone — probably Dr. P. H. Carpenter — in going over the collection of 

 the Berlin Museum discovered this specimen and separated it out from the type series 

 of Alecto savignii, labeling it Antedon ludovici. 



It was under this name that I found it in 1910. In 1911 I described it under the 

 name of Craspedometra ater. In 1912 in my memoir on the crinoids of the Berlin 

 Museum I again mentioned it, giving the early references to Miiller. 



In my report on the unstalked crinoids of the Siboga expedition it was included in 

 the key to the species of the genus Heterometra. In this report I referred to H. ati r 

 the specimen from Ceylon identified as Craspedometra amboinae by Reichensperger. 

 I am now convinced thai Reichensperger's identification was correct and that the 

 Ceylon specimen really represents amboinae. 



HETEROMETRA JOUBINI (A. H. Clark) 



llcicrometra joubini A. II. 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 de- 

 scription; Zanzibar); Crinoids of the Indian Ocean, 1912, p. 127 (synonymy; habitat); Un- 



