A MONOGKAPH OF THE EXISTING CRINOIDS 457 



Genus COMANTHINA A. H. Clark 



Actinometra (part) P. H. Carpenter, Notes from the Leyclen Mus., vol. 3, 1881, p. 210, and fol- 

 lowing authors. 



Adinometra (part) Koehler, Mi-m. de la soc. zool. de France, vol. 8, 1895, p. 450. 



Comasler (part) A. H. Clark, Proc. U. S. Nat. Mus., vol. 33, 1908, p. 686. 



Phanogenia (part) A. H. Clark, Proc. U. S. Nat. Mus., vol. 35, 1908, p. 124. 



Comanlhus (part) A. H. Clark, Smiths. Miscell. Coll., vol. 52, pt. 2, 1908, p. 204. 



Comanlhina A. H. Clark, Videnslc. Medd. fra den naturhist. Forening i K0benhavn, 1909, p. 

 142 (diagnosis; genotype Actinometra nobilis P. H. Carpenter, 1888); Memoirs Australian Mus., 

 vol. 4, pt. 15, 1911, p. 733 (in key; ke}- to the Australian species); p. 752 (original reference: 

 characters; range); Crinoids of the Indian Ocean, 1912, p. 9 (in Australia distinctive local 

 species supplant the common East Indian species); p. 10 (does not e.xtend beyond Hong Kong; 

 absent from Japan; reason); p. 11 (represented in the Ceylon region; this the western limit 

 of the large and highly multibrachiate forms); pp. 55, 56 (in keys); p. 91 (original reference; 

 type); American Naturalist, vol. 49, 1915, p. 525 (bathymetric range); p. 539 (asymmetrical 

 disk; 1 or more rays dwarfed); Unstalked Crinoids of the Siboga Exped., 1918, p. 34 (in key; 

 range). — Gislen, Nova Acta reg. Soc. sci. Upsaliensis, ser. 4, vol. 5, No. 6, 1922, p. 52 (pinnule 

 combs); p. 56 (discussion). 



Comanthus (Comanthina) A. H. Clark, Vidensk. Medd. fra den naturhist. Forening i K0benhavn, 

 1909, p. 143. 



Diagnosis.— A genus of Comasterinae in which the elements of the IBr series 

 and the first 2 ossicles following each axillary are united by synarthry; most of the 

 axUlaries bear either 2 division series or 2 arms; the IIBr series are 4 (3 + 4), and the 

 IIIBr series are on the outer side of each ray 2 and on the inner side 4 (3 + 4), though 

 this typical arrangement is subject to some variation, especially ou posterior arms 

 following IIBr 2 series. 



Geographical range. — From the Macclesfield Bank and the Philippine, CaroUne, 

 and Solomon Islands to Queensland and the Abrolhos Islands, Western AustraUa, 

 and westward to the Maldive Islands. 



Bathymetrical range. — From the shore Hne down to 548 meters; but both the 

 included species are chiefly sublittoral. 



Remarks. — When fully grown the species of this genus have a characteristically 

 massive appearance which distinguishes them at once. The division series are very 

 broad and are flattened dorsally, and the perisomic areas between the division series 

 and arm bases are always completely covered with a solid pavement of heavy plates. 



The number of arms in C. schlegelii may reach 200, the largest number found 

 in any comatulid. In C. belli there may be 150 or more arms. 



The division series are subject to more or less irregularity, the outer IIIBr 

 series being rather often 4 (3 + 4) instead of the normal 2; but the typical arrangement 

 is almost invariably to be foimd on at least one raj\ 



The terminal combs are confined to the lower pinnules, and as a ride do not 

 extend beyond P? or Pg, though in C. schlegelii they may occur at intervals as far 

 as Pjo- 



Cirri are usually absent in C. schlegelii, though from 1 to 5 or 6 — rarely more — 

 may be present. In C. belli cirri may be absent, but a small niunber are usually 

 present. 



Whereas the adults of the two species of Comanthina are among the easiest of 

 the comatulids to identify, young individuals, especially of C. belli, are exceedingly 



