532 BULLETIN 82, UNITED STATES NATIONAL MUSEUM VOLUME 1 



plates, the basals and orals, its stalk of 10 or more stout columnals and a large terminal 

 plate. Dr. John said that whether this stage represented the farthest to which the 

 pentacrinoid larvae develop before being released from the brood pouch cannot be 

 determined. No pentacrinoids are attached to any part of either of the two specimens. 



So far as can be seen the disk is not plated. The anal cone is very high, higher 

 than the level of the second syzygy. 



The sacculi on the distal pinnules are regularly arranged. 



In the perisome of the pinnules there are 3 or 4 side plates to a segment. Each 

 is a long straight rod arising from a branching or reticulate base with the distal end 

 thorny or slightly branched, or expanded into a small reticulate plate smaller than 

 that at the base. The plates of the proximal segments are more simple, those of the 

 distal more complex. Continuous with the end of each plate is a row of knobbed and 

 curved rods, the end of one overlapping that of the next, arranged in an arc which 

 travels backward (toward the base of the pinnule) and inwards; they appear to lie 

 along the edges of the marginal lappets. Dr. John found no spicules in the tentacles. 



The color in life was described as "Dark grey markings on a white ground. General 

 effect grey." In alcohol the color is the same, even after 20 years. The dorsal surface 

 of the elements of the IBr series, and of the brachials, is dusky gray, though the prox- 

 imal edges of the brachials, like the muscular articulations, may be white. The pin- 

 nules, especially the lower segments of the distal pinnules, are of a darker color than 

 the brachials; the slightly swollen articulations are white. The cirri appear white in 

 comparison with the rest of the animal; a few of the basal segments, the penultimate 

 and one or two of those preceding it, may be of a darker tinge. The terminal claw is 

 hyaline. The disk is yellowish; the anal cone and the ambulacra of the disk, arms, 

 and pinnules are darkly pigmented. 



Locality. Discovery Investigations station 1957; 7 miles east of Cape Bowles, 

 Clarence Island, South Shetlands; 830 meters; bottom rough and stony; February 3, 

 1937 [John, 1938] (2, B.M.). 



History. Two females of this species were dredged by the Discovery in 1937 and 

 were described by Dr. D. Dilwyn John hi the following year. Dr. John was so land 

 as to send me one of the specimens for examination, but I have nothing to add to his 

 excellent description. 



Genus CYCLOMETRA A. H. Clark 



Cyclometra A. H. CLARK, Proc. U.S. Nat. Mus., vol. 40, 1911, p. 51 (in combination Cyclometra jlaves- 

 cens, nomen nudum); Proc. Biol. Soc. Washington, vol. 24, 1911, p. 87 (diagnosis; type species 

 Cyclometra flavescens sp. nov.; referred to subfamily Heliometrinae) ; Mem. Australian Mus., 

 vol. 4, 1911, p. 727 (Heliometrinae); Crinoids of the Indian Ocean, 1912, p. 11 (part), p. 12 (in 

 Red Sea area), p. 26 (part) (range; relationships), p. 62 (in key), p. 238 (diagnosis; type species); 

 Internat. Rev. gesamt. Hydrobiol. und Hydrogr., vol. 6, 1914, pp. 5 and following (range); 

 Die Crinoiden der Antarktis, 1915, pp. 122-126 (characters; relationships; origin), p. 126 (part) 

 (included species and ranges), p. 182 (discussion); Journ. Washington Acad. Sci., vol. 7, No. 5, 

 1917, p. 127 (Heliometrinae); No. 16, p. 508 (in key; range); Unstalked crinoids of the Siboga- 

 Exped., 1918, p. 240 (in key; range), p. 244 (part) (key to the species); John Murray Exped. 

 1933-34, Sci. Reports, vol. 4, No. 4, 1937, p. 105 (single specimen known). GISL^N, Rep. Swedish 

 Deep Sea Exped., vol. 2, Zool., No. 4, 1951, pp. 55, 56 (bathymetrical range). A. H. CLARK, 

 Trans. Roy. Soc. South Africa, vol. 33, pt. 2, 1952, p. 189 (C. multicirra sp. nov.), pp. 191, 192 

 (referred to Zenometrinae; notes on the type of C. flavescens). 



