PABT 5 A MONOGRAPH OF THE EXISTING CRINOIDS 773 



obliquely wedge-shaped or practically triangular, about as long as broad, and distally 

 wedge-shaped again and much longer than broad, as much as 4 or 5 times as long as 

 broad in the terminal brachials. The brachials from the second to the ninth inclusive 

 are rather disproportionately large and very strongly tubercular. 



Syzygies occur between brachials 4 + 5, 9 + 10, and distally at intervals of from 

 2 to 4 (usually 3 or 4) muscular articulations. 



The second brachial bears a pinnule, PI. The genital pinnules bear short rounded 

 gonads. 



Locality. Albatross station 4157; Hawaiian Islands, in the vicinity of Modu 

 Manu, or Bird Island; center of Bird Island bearing S. 7730' E., 11.1 miles distant; 

 1393-1828 meters; temperature 3.33 C.; white mud, Foraminifera, and rocks; August 

 6, 1902 [A. H. Clark, 1908] (1, U.S.N.M., 22682). 



Remarks. As yet this species is only known from the single much broken 9-rayed 

 specimen described above. 



THAUMATOCRINUS NARESI (P. H. Carpenter) 



[See vol. 1, pt. 1, fig. 114, p. 181] 



Promachocrinus naresii P. H. CARPENTER, Proc. Roy. Soc., vol. 28, 1879, p. 385 (nomen nudum) ; 

 Nature, vol. 19, 1879, p. 450 (nomen nudum). 



Promachocrinus naresi P. H. CARPENTER, Challenger Reports, Zoology, vol. 26, pt. 60, 1888, p. 352 

 (description; Challenger sta. 214); pi. 69, figs. 8-10. HAMANN, Bronn's Klassen und Ordnungen 

 des Tier-Reichs, vol. 2, Abt. 3, 1907, p. 1576 (listed). A. H. CLARK, Crinoids of the Indian Ocean, 

 1912, p. 33 (of P. H. Carpenter, l888 = Decametrocrinus naresi); Die Crinoiden der Antarktis, 

 1915, p. 120 (belongs to the Pentametrocrinidae; = Thaumatocrinus naresi). 



Decametrocrinus naresi MINCKERT, Zool. Anz., vol. 28, No. 13, 1905, p. 501. A. H. CLARK, Proc. 

 U.S. Nat. Mus., vol. 34, 1908, p. 216 (compared with D. rugosus); Crinoids of the Indian Ocean, 

 1912, p. 33 (= Promachocrinus naresi P. H. Carpenter, 1888), p. 248 (synonymy; includes 

 D. borealis A. H. Clark, 1907; range). 



Thaumatocrinus naresi A. H. CLARK, Smithsonian Misc. Coll., vol. 61, No. 15, 1913, p. 66 (published 

 references to specimens in B.M.; Challenger sta. 214; comparison with T. borealis) ; Die Crinoiden 

 der Antarktis, 1915, p. 150 (in key; range); Unstalked crinoids of the Siboga-Exped., 1918, p. 260 

 (in key; range; notes; sta. 122), p. 273 (listed); fig. 14, p. 260. GISLN, Ark. Zool., vol. 19, 

 No. 32, 1928, p. 12 (notes). 



Diagnostic features. The centrodorsal is flattened hemispherical, 5.5 and 9 mm. 

 in diameter in the two specimens known, with about XL and LX cirrus sockets respec- 

 tively; the articular tubercles on the proximal brachials are not very prominent. 



Description [by A.M.C.]. The centrodorsal is flattened hemispherical, 9 mm. in 

 diameter at the base, 3.5 mm. in height and the diameter of the dorsal pole between the 

 cirrus sockets is 4 mm. There are LX sockets alternating hi position in about three 

 irregular rows around the sides of the ceutrodorsal. 



No cirri remain but a terminal fragment of one with 6 segments and measuring 

 8 mm. was found in the jar, which presumably comes from this specimen. The terminal 

 claw is short, blunt, and hardly at all inclined dorsally. The penultimate segment is 

 twice as long; it has no opposing spine and even tapers very slightly towards the distal 

 end; it is half again as long as broad. The other segments have similar proportions 

 but are a little wider dorsoventrally and the first three are 'slightly expanded in the same 

 plane towards their distal ends. 



The edges of the radials are visible beyond the edge of the centrodorsal. The first 

 brachials are short, 1.2 mm. long in the dorsal midliue. The second ones are 1.9 mm. 



