448 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



COMASTER DISTINCTA (P. H. Carpenter) 



Plate 52, Figure 153 



[See also vol. 1, pt. 1, fig. 320 (cirri), p. 275; pt. 2, figs. 418, 419 (pinnule tip), p. 255; figs. 638-642 

 (combs), p. 323] 



Comatula, sp. P. H. CARPENTER, Trans. Linn. Soc. (Zool.), ser. 2, vol. 2, 1879, p. 23, footnote 5. 



Actinometra, sp. (part) P. H. CARPENTER, Trans. Linn. Soc. (Zool.), ser. 2, vol. 2, 1879, p. 41, 

 footnote S. 



Actinometra distincta P. H. CARPENTER, Challenger Reports, Zoology, vol. 26, pt. 60, 1888, p. 295 

 (description; Samboangan, 10 fathoms; discussion); pi. 55, fig. 1. HARTLAUB, Nova Acta 

 Acad. German., vol. 58, No. 1, 1891, p. 109 (systematic position). HAMANN, Bronns Klassen 

 u. Ordnungen des Tier-Reichs, vol. 2, Abt. 3, 1907, p. 1584 (listed). A. H. CLAKK, Proc. 

 U. S. Nat. Mus., vol. 33, 1908, p. 684 (assigned by Carpenter to the Typica group); Memoirs 

 Australian Mus., vol. 4, pt. 15, 1911, p. 748 (same); Crinoids of the Indian Ocean, 1912, p. 35 

 (identity). 



Actinometra parvicirra (part) P. H. CARPENTER, Challenger Reports, Zoology, vol. 26, pt. 60, 1888, 

 p. 338 (Samboangan, 10 fathoms) . 



Comatula distincta A. H. CLARK, Proc. U. S. Nat. Mus., vol. 33, 1908, p. 685 (listed); vol. 35, 1908, 

 p. 124 (listed). 



Phanogenia distincta A. H. CLARK, Smiths. Miscell. Coll., vol. 52, pt. 2, 1908, p. 203, footnote 

 (arm structure; systematic position). 



Comaster distincta A. H. CLARK, Proc. U. S. Nat. Mus., vol. 39, 1911, p. 533 (Albatross stations 

 5356, 5401, 5414, 5477; compared with C. serrata and C. parvus); Crinoids of the Indian Ocean, 

 1912, p. 35 ( = Actinometra distincta P. H. Carpenter, 1888); p. 36 ( = A. parvicirra P. H. Car- 

 penter, 1888, part); p. 38 ( = Antedon brevicirra Bell, 1894); p. 87 (synonymy; summary of 

 previous records; range); Smiths. Miscell. Coll., vol. 61, No. 15, 1913, p. 13 (published refer- 

 ences to specimens in the British Museum; localities represented [specimens from Macclesfield 

 Bank = &mricirra]; characters of the specimens); Unstalked Crinoids of the Siboga Exped., 

 1918, p. 37 (in key; range); p. 41 (references; stations 65C, 144, 153, 260, 289,294, 305); p. 42, 

 fig. 2 (normal and abnormal cirri); pp. 272, 273, 275, 276 (listed). GISLEN, Kungl. svenska 

 Vetenskap. Handl., vol. 59, No. 4, 1919, pp. 14, 15 (discussion). 



Diagnostic features. The arms are 30-35 in number. The cirri have 9-13 

 segments, of which the longest is about twice as long as broad. This species is 

 distinguished from brevicirra by the fewer arms, from pulcher by the fewer cirrus 

 segments, from serrata by the lesser elongation of the longest cirrus segments, and 

 from tenella by the greater number of arms. 



Description. The centrodorsal is a thick circular disk with the cirrus sockets 

 arranged in 2 irregular and more or less alternating rows. 



The cirri are about XXX, 12. Nearly all of the cirrus segments are longer than 

 broad, and the distal have slight dorsal spines. 



The radials are just visible beyond the rim of the centrodorsal. The IBri are 

 in contact laterally. The elements of the IBr series are short and broad, and are 

 united by syzygy. The IIBr series are 4 (3 + 4). The IIIBr series are 2 (1 + 2). 



There are, in the type specimen, 36 arms which are about 60 mm. long. The 

 earlier brachials are oblong, the majority are triangular, broader than long, and the 

 distal are wedge-shaped. The brachials have somewhat produced and overlapping 

 distal ends. The anterior arms are long, slender, and slowly tapering, with 120-150 

 brachials. The posterior arms are shorter, rapidly tapering, with only 60-80 brachials. 

 All of the arms are grooved. 



