A MONOGRAPH OF THE EXISTING CRINOIDS 293 



Subfamily COMACTINHNAE A. H. Clark 



Comactiniinae A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 175 (includes Comatula, 

 Comaclinia, and Cominia [Comatulides]); Die Fauna Siidwest-Australiens, vol. 3, Lief. 13, 1911, 

 p. 438 (2 genera and 6 species in Australia); Proc. U. S. Nat. Mus., vol. 43, 1912, p. 390 (dis- 

 cussion of characters) ; Crinoids of the Indian Ocean, 1912, p. 6 (number of East Indian genera; 

 number of genera also found in the Atlantic; number of genera represented by closely allied 

 genera in the Atlantic; genera exclusively confined to the East Indies; number of East Indian 

 species); p. 20 (distribution in detail); p. 54 (in key); Bull, de 1'Institut ocfianographique, 

 Monaco, No. 294, 1914, pp. 7, 8 (relations to temperature); Journ. Washington Acad. Sci., 

 vol. 4, No. 19, 1914, pp. 559-563 (correlation of geographical and bathymetrical range) ; No. 20, 

 p. 582 (relation to temperature); Internal. Revue d. gesamt. Hydrobiol. u. Hydrogr., 1914, 

 pp. 4 and following (Atlantic and corresponding East Indian genera); Records of the Western 

 Australian Museum, vol. 1, pt. 3, 1914, p. 114 (genera and species collected by the Endeavour 

 in Western Australia); Journ. Washington Acad. Sci., vol. 5, No. 4, 1915, pp. 126-134 (bathy- 

 metrical range and its phylogenetic and palaeontological significance) ; Amer. Journal of Science, 

 vol. 40, 1915, p. 67 (detailed discussion of bathymetrical range); American Naturalist, vol. 49, 

 1915, p. 525 (bathymetrical and thermal ranges; included genera and their bathymetrical 

 ranges); p. 539 (genera with asymmetrical disks; genus with one or more rays dwarfed); Un- 

 stalked Crinoids of the Siboga Exped., 1918, p. 2 (in key); p. 24 (key to the included genera); 

 University of Iowa, Studies in Nat. Hist., vol. 9, No. 5, 1921, p. 12 (represented in West Indies) ; 

 p. 25; Smithsonian Miscell. Coll., vol. 72, No. 7, 1921, p. 3. 



Comactiniincs A. H. CLARK, Bull, du mus. d'hist. nat., Paris, No. 4, 1911, p. 247. 



Diagnosis. A subfamily of Comasteridae in which the cirri are usually short 

 and strongly curved, and their outer segments are entirely without dorsal processes; 

 the cirri are often entirely absent, and may be present only in the interradial angles 

 of the centrodorsal ; the arms are usually 10, but sometimes more than 10, though 

 never more than 23, in number; when there are more than 10 arms the IIBr and IIIBr 

 series are always 2 (1+2); following a IIBr or IIIBr axillary, and often following a 

 IBr axillary, the first brachial syzygy, always on the outer arms and sometimes on 

 both, is between brachials 1 + 2, and there is another syzygy between brachials 3 + 4; 

 the genital pinnules are usually, but not invariably, noticeably broadened and are 

 composed of very short segments. 



Geographical range. From southwestern Japan [?and the Society Islands] to 

 the southern coast of Australia and westward to Ceylon; from Cape Lookout, N. C., 

 southward throughout the Caribbean Sea and Gulf of Mexico to Rio de Janeiro, 

 Brazil. 



Bathymetrical range. From the low-tide mark down to 984 meters. The rela- 

 tive frequency of the included genera at different depths is as follows: 



0-100 meters 3 



100-200 meters 2 



200-300 meters.- 1 



300-400 meters 2 



400-600 meters 2 



600-1,000 meters 1 



Remarks. The subfamily Comactiniinae is a small and fairly homogeneous group 

 including only 4 genera. Three of the four genera (Comatulella, Comactinia and 

 Comatulides) contain species with 10 arms only. Of the 7 species included in the 

 fourth genus (Comatula) 5 have invariably 10 arms, 1 is normally 10-armed, but 

 certain individuals occur with more than 10 (usually 11 or 12, but exceptionally as 

 many as 17) arms, and the last has 20 arms. 



