A MONOGRAPH OF THE EXISTING CRINOIDS 489 



382. HAMANN, Bronns Klassen u. Ordnungen dcs Tier-Rcichs, vol. 2, Abt. 3, 1907, p. 1586 

 (listed). A. H. CLARK, Notes from the Leydon Mus., vol. 33, 1911, p. 176 (identity of type 

 specimen); Memoirs Australian Mus., vol. 4, 1911, p. 714 (of Alert report = allernans); p. 710 

 (credited to Australia by Carpenter); Crinoids of the Indian Ocean, 1912, p. 31 (of Alert 

 report = alternans.); p. 36 (of P. H. Carpenter, I8&8 = alternanr); Smiths. Miscell. Coll., vol. 61, 

 No. 15, 1913, p. 75 (identity of Bell's specimens). 



Comasler alternant A. H. CLARK, Proc. U. S. Nat. Mus., vol. 33, 1908, p. 686 (listed). 



Phanogenia alternant A. H. CLABK, Proc. U. S. Nat. Mus., vol. 35, 1908, p. 124 (listed). 



Comanlhus alternans A. H. CLARK, Proc. U. S. Nat. Mus., vol. 36, 1909, p. 397 (Albatross stations 5252, 

 5254); Zool. Anzeiger, vol. 34, No. 11-12, 1909, p. 366 (listed). H. L. CLARK, Recoids Western 

 Australian Mus., vol. 1, pt. 3, 1914, p. 134 (Abrolhos Is.; characters); Carnegie Institution of 

 Washington Publication 212, 1915, p. 101 (Mer; 18 fathoms); The Echinoderm Fauna of Torres 

 Strait, 1921, p. 8 (secured by the Carnegie Exped.) ; p. 17 (range; single specimen found at Mer; 

 reactions); pi. 20, fig. 1; Journ. Linn. Soc. (Zool.), vol. 35, 1923, p. 231 (Western Australia). 



Comanlheria alternans A. H. CLARK, Notes from the Leyden Mus., vol. 33, 1911, p. 176 (identity); 

 p. 178 (no locality; redescription of the type); Die Fauna Sudwest-Australien^, vol. 3, Lief. 13, 



1911, p. 439 (East Indian species occurring south to Port Molle); p. 443 (lange on the east 

 coast); Memoirs Australian Mus., vol. 4, 1911, p. 717 (known to Carpenter from Australia); 

 p. 721 (occurs south to Port Molle); p. 733 (in key); p. 751 (annotated synonymy; characters; 

 Port Molle; distribution; description of the type at Leyden); Crinoids of the Indian Ocean, 



1912, p. 31 ( = Aclinometra alternans Bell, 1884); p. 36 ( = Actinomeira allcrnans P. H. Carpenter, 

 1888); p. 90 (synonymy; sammary of previous records; description of the type); Smiths. 

 Miscell. Coll. vol. 61, No. 15, 1913, p. 13 (published reference to the specimen in the British 

 Museum; Port Molle, 12-20 fathoms, rock); p. 75 ( = Actinometra alternans Bell, 1884, part). 

 REICHENSPEHGER, Abhandl. Senck. naturf. Gesellsch., vol. 35, Heft 1, 1913, p. 83 (Amboina); 

 p. 87 (Amboina; Professor Strubell; characters of the specimen). A. H. CLARK, Internat. 

 Revue d. gesamt. Hydrobiol. a. Hydrogr., 1915, pp. 222 and following (detailed account of the 

 distribution in Australia) ; Unstalked Crinoids of the Siboga Exped., 1918, p. 43 (in key; range). 



Comanthus polycnemis H. L. CLARK, Records Western Australian Mus., vol. 1, pt. 3, 1914, p. 135 

 (Abrolhos Is.; characters of the specimen); Journ. Linn. Soc. (Zool.), vol. 35, 1923, p. 231 

 (Western Australia). 



Diagnostic features. A very large species -with very numerous arms and a small 

 stellate centrodorsal. The IIBr series are 4 (3 + 4), the IIIBr series are 2, the IVBr 

 series are 4 (3+4), the VBr series are 2, and the VIBr series, if present, are 4 (3+4). 

 There may be a reversal of the sequence on some of the rays, but the alternation is 

 always evident. 



In general appearance this species resembles briareus rather than polycnemis. 



Description. The centrodorsal is a pentagonal disk with more or less concave 

 sides, flat or slightly hollowed in the center, its dorsal surface slightly higher than the 

 dorsal surface of the radials. There are no distinct traces of functional cirrus sockets. 



There are no cirri. 



The ends of the basal rays are visible as low tubercles at the angles of the cen- 

 trodorsal. 



The radials are very short. The IB^ are about twice as long as the radials and 

 are almost entirely united laterally. The IBr 2 (axillaries) are triangular, scarcely half 

 again as long as the IBr^ nearly three times as broad as long, and laterally free. 

 The IIBr series are 4 (3 + 4); the IIIBr series are 2; the IVBr series are 4 (3 + 4); 

 the VBr series are 2; the VIBr series are 4 (3+4). VIBr series are rare or absent, 

 and the VBr series also are usually more or less deficient. Beyond the IBr series the 



