84 BULLETIN 8 2, UNITED STATES NATIONAL MUSEUM 



ANALCIDOMETKA CARIBBEA (A. H. Clark) 



Plate 9, Figure 47 



Antedon armala (part) P. H. Carpenter, Challenger Reports, Zoology, vol. 26, part 60, 1888, pp. 54, 

 207. 376.— Hartlaub, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 394 (one of the two 

 larger specimens) ; pi. 7, figs. 3, 4; pi. 13, fig. 7, left. 



Oligomelra caribbea A. H. Clark, Proc. Biol. Soc. Washington, vol. 21, 1908, p. 126 (listed; nomen 

 nudum); Proc. U. S. Nat. Mus., vol. 34, 1908, p. 238 (description; Albatross station 2146); 

 Proc. Biol. Soc. Washington, vol. 22, 1909, p. 7 (listed), p. 42 (compared with 0. sluderi) ; Mem. 

 Australian Mus., vol. 4, 1911, p. 779, footnote (referred to the genus Analcidometra) ; Crinoids 

 of the Indian Ocean, 1912, p. 22 (0. caribbea, type of Analcidometra, represents the family 

 Stephanometridae in the western Atlantic). 



Analcidometra caribbea A. H. Clark, Mem. Australian Mus., vol. 4, 1911, p. 779 (resembles Oligo- 

 melra [Ausiromctra] thetidis). 



Analcidometra armata (part) A. H. Clark, The Danish Ingolf-Exped., vol. 4, No. 5, Crinoidea, 

 1923, p. 39 (Colon, 64 meters; other localities and depths refer to A. armata). 



Diagnostic features. — Pi is shorter and less stout than P2, though of the same 

 character; the proximal pinnules are stiffened, but are not greatly enlarged. This 

 little species is easily recognized by the short stout cirri composed of segments most 

 of which are about as long as broad, and of which the proximal bear conspicuous 

 transverse ridges, and by having P2 the longest and stoutest of the proximal pinnules. 



Description. — The centrodorsal is thick discoidal, 2 mm. in diameter, with slightly 

 sloping sides and a slightly concave roughened or finely and sparsely papillose dorsal 

 pole. The cirrus sockets are arranged in a single very irregular marginal row, often 

 with obsolescent or obsolete sockets below or young cirri above the functional cirri. 



The cirri are X-XV, 23, moderately stout, often tapering slightly distally. The 

 first segment is between three and four times as broad as long, the second is about 

 three times as broad as long, the third is about twice as broad as long, the foiu-th is 

 nearly as long as broad, and those following are about as long as broad. The first 

 segment has a single or paired tubercle or more or less broad production in the middle 

 of the distal dorsal edge, or if there be an obsolescent cutus socket below it, a pointed 

 tubercle or pair of tubercles on either side on the dorsolateral margin. The second 

 segment has the distal dorsal edge produced, the production being more or less 

 depressed in the middle and highest laterally with the edge scalloped or coarsely 

 dentate, or thickened and produced in the middle; there is usually a prominent 

 pointed dorsolateral tubercle on either side. The third segment has the distal dorsal 

 edge produced into a coarsely dentate transverse ridge terminated on either side by 

 one or two pointed dorsolateral tubercles, or the central portion of the distal dorsal 

 edge is thickened and raised into a broad low tubercle. On the fourth segment the 

 dorsal distal edge may be raised into a transverse ridge as on the third, or the trans- 

 verse ridge may be resolved into 5-pointed tubercles one of which is central, or it 

 may be more or less strongly bowed proximally and interrupted in the middle. On 

 the sixth segment there is a prominent pointed tubercle, or sometimes a pair of 

 tubercles, on the dorsolateral portions of the distal dorsal border, and between these 

 in the median line a larger pointed tubercle just within the distal edge. The segments 

 succeeding bear a large pointed tubercle in the midline which at first is just within 

 the distal edge but soon moves to a central position, on either side of which is a smaller 

 tubercle situated on the dorsolateral portion of the distal edge. On the last five to 

 nine segments before the penultimate the lateral tubercles disappear and there is 



