90 BULLETIN 82, UNITED STATES NATIONAL 



Comatella A. H. CLARK, Smiths. Miscell. Coll., vol. 52, part 2, 1908, p. 207 (diagnosis; genotype 

 Actinometra nigra P. H. Carpenter, 1888; arm division); Proc. U. S. Nat. Mus., vol. 36, 1909, 

 p. 365 (mouth nearly or quite central); p. 506 (synonymy; genotype; range); Proc. Biol. Soc. 

 Washington, vol. 22, 1909, p. 175 (referred to the Capillasterinae) ; Vidensk. Medd. fra den 

 naturhist. Forening i K0benhavn, 1909, p. 193 (probably occurs at Singapore, though not yet 

 discovered there); Proc. U. S. Nat. Mus., vol. 40, 1911, p. 10 (represented in the West Indies 

 by Neocomatella) ; p. 13 (common to southeast Africa and Ceylon, though not occurring in the 

 Arabian Sea); Ann. and Mag. Nat. Hist., ser. 8, vol. 7, 1911, p. 644 (falls in the same family as 

 Comissia); Memoirs Australian Mus., vol. 4, part 15, 1911, p. 730 (in key); p. 732 (in key; key 

 to the Australian species); p. 738 (original reference; characters; range; N eocomatella a repre- 

 sentative); p. 741 (arm division); Proc. Biol. Soc. Washington, vol. 25, 1912, p. 18 (cirri com- 

 pared with those of Palaeocomalella); Proc. TJ. S. Nat. Mus., vol. 43, 1912, p. 390 (represented 

 in the West Indies by N eocomatella) ; Crinoids of the Indian Ocean, 1912, p. 11 (represented in 

 the Ceylon region which is the western limit of the large highly multibrachiate species) ; p. 12 

 (represented in the southeast African region) ; p. 13 (corresponds to the West Indian 

 N eocomatella); p. 20 (bathymetric range); p. 55 (in key); p. 68 (original reference; type); 

 Intemat. Revue d. gesamt. Hydrobiol. u. Hydrogr., 1914, pp. 3 and following (represents 

 Neocomatella; range); Beitrage zur Kenntnis d. Meeresf. Westafrikas, Echinod. II, Crinoidea, 

 1914, p. 309 (Indo-Pacific genus occurring at Madagascar and represented in the central Atlantic 

 by Neocomatella); Die Crinoiden der Antarktis, 1915, p. 181 (range; represented in the Atlantic 

 by Ncocomalella); American Naturalist, vol. 49, 1915, p. 525 (bathymetric range); p. 539 (asym- 

 metrical disk); Unstalked Crinoids of the Siboga Exped., 1918, p. 3 (in key); p. 4 (key to the 

 included species). GISLISN, Zool. Bidrag fran Uppsala, vol. 9, 1924, pp. 35, 38 (brachial 

 homologies). 



Diagnosis. A genus of Capillasterinae in which the arms are more than 10 in 

 number, all of the division series are 2, the first pinnule of the undivided arms is on 

 the second brachial ; the first syzygy is between brachials 1+2 except on the outer- 

 most arms of each ray where it is between brachials 3 + 4 ; and the brachials beyond 

 the basal are short, broader than long, and wedge-shaped. 



Geographical range. Salomon, Coin Peros, the Maldive Islands, and Ceylon to 

 the Abrolhos Islands, Western Australia, Torres Straits, New Caledonia, Tonga, Fiji, 

 Samoa, the Bonin Islands, southwestern Japan, the Philippines, and Macclesfield 

 Bank. 



Bathymetrical range. From the shore line down to 210 meters. 



Thermal range. From the very warm water of the tropical littoral down to at 

 least 13.28 C.; there is, however, only a single definite record. 



Remarks. In their general structure the species of this genus are all very similar, 

 differing chiefly in size and in features commonly correlated with size, such as the num- 

 ber of arms and cirrus segments, and the number of comb-bearing proximal pinnules. 



The number of cirrus segments varies from 9-12 in C. brachycirra to 25-31 in 

 C. nigra, but in all the species the cirri are of the same type. The centrodorsal is 

 always discoidal, more or less thick, with the broad dorsal pole becoming more con- 

 cave and developing a median rounded pit as the thickness increases. The cirri are 

 arranged in from one to three or more closely crowded and irregular marginal rows. 



Because of the close similarity in the form of the centrodorsal and in the structure 

 of the cirri, the large species of this genus have a very considerable superficial resem- 

 blance to the species of Capillaster of corresponding size with which, until the division 

 series are examined, they are likely to be confused. The general appearance of the 

 small species is, however, very characteristic. 



