284 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



In 1913 I recorded some specimens from Cuba which I had studied at the British 

 Museum in 1910. 



Among the specimens from the University of Iowa's Bahamas expedition which 

 were recorded by Dr. Hubert Lyman Clark in 1918 under the name of Comactinia 

 echinoptera I found an example of this form from station 7. 



In 1921 I recorded this species from a number of different stations about Barba- 

 dos, and in 1923 I gave its range as worked out from my unpublished notes. 



Genus COMATILIA A. H. Clark 



Comatilia A. H. CLARK, Proc. U. S. Nat. Mus., vol. 36, 1909, p. 365 (diagnosis; type C. iridometri- 

 formis, sp. nov.); p. 497 (original reference, genotype, and range); Proc. Biol. Soc. Wash- 

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

 hist. Forening i K0benhavn, 1909, p. 132 (side plates only) ; p. 151 (comparison with Cominia); 

 Proc. U. S. Nat. Mus., vol. 38, 1910, p. 331, footnote (has 5 interradials when young); Ann. 

 and Mag. Nat. Hist., ser. 8, vol. 7, 1911, p. 644 (with Leptonemaster represents Comissia in 

 the West Indies); Proc. U. S. Nat. Mus., vol. 40, 1911, p. 654 (central mouth); American 

 Journ. Sci., ser. 4, vol. 32, 1911, p. 129 (characteristic of the West Indian fauna; significance); 

 Crinoids of the Indian Ocean, 1912, p. 13 (corresponds to the East Indian Comissia, part); 

 Internat. Revue der gesamt. Hydrobiol. u. Hydrogr., 1914, pp. 3 et seq. (represents Comissia, 

 in part, in the Atlantic; range and its significance); Die Crinoiden der Antarktis, 1915, p. 132 

 (covering plates); p. 181 (range; representative in the Atlantic of the Indo-Pacific Comissia, 

 part); American Naturalist, vol. 49, 1915, p. 525 (asymmetry absent); Unstalked Crinoids 

 of the Siboga Exped., 1918, p. 4 (in key). BATHER, Ann. and Mag. Nat. Hist., ser. 9, vol. 1, 

 No. 4, April, 1918, p. 298 (interradials). A. H. CLARK, Univ. Iowa, Studies in Nat. Hist., 

 vol. 9, No. 5, 1921, p. 12 (confined to the West Indies); p. 15 (in key); The Danish Ingolf- 

 Exped., vol. 4, No. 5, Crinoidea, 1923, p. 39 (range); p. 50 (in key). 



Diagnosis. A genus of Capillasterinae including small species with 10 arms only 

 and a central mouth; the second, third, and fourth pairs of pinnules are absent, so 

 that there are no pinnules between PI and P 6 on the outer and P a and P, on the inner 

 side of the arms. 



Geographical range. Only known from east of Brunswick, Ga. 



Bathymetrical range. Only known from 512 meters. 



Thermal range. One record, 6.95 C. 



Remarks. This is the only genus of Comasteridae with deficient pinnulation, 

 with large and well-formd covering plates along the pinnule ambulacra, and with 

 perisomic interradials. 



In the Oligophreata deficient pinnulation occurs elsewhere only in the family 

 Colobometridae, where the absence of one (rarely more) of the earlier pinnules 

 (usually P a ) is widespread, being found in the genera Petasometra, Cyllometra, Epi- 

 metra, Colobometra, Cotylometra (by individual variation), Prometra, Decametra, and 

 Oligometra (by individual variation). In the Macrophreata it reaches an extreme in 

 the Atelecrinidae in the genus Atelecrinus, though the other genus of that family, 

 Atopocrinus, has the full complement of pinnules. In the Pentametrocrinidae 

 deficient pinnulation is characteristic of all the species of Thaumatocrinus and of some 

 of the species of Pentametrocrinus. In the Antedonidae it occurs in Balanometra 

 (Zenometrinae), and in Hypalometra and occasionally by individual variation in 

 Erythrometra and Perometra (Perometrinae) . Groups of perisomic interradials 

 resembling those of Comatilia are characteristic of the Atlantic species of Antedon, 

 of species of some closely allied genera, and of Erythrometra. 



