A MONOGRAPH OF THE EXISTING CKINOIDS 289 



Comalonia A. H. CLARK, Journ. Washington Acad. Sci., vol. 6, 1916, No. 5, p. 115 (type Actinometra 

 cristata [P. H. Carpenter, MS.] Hartlaub, 1912; diagnosis; range); Unstalked Crinoids of the 

 Siboga Exped., 1918, p. 4 (in key); 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, 

 p. 39 (range) ; p. 51 (in key). GISLEN, Zool. Bidrag fran Uppsala, vol. 9, 1924, p. 229, footnote 1 

 (anomalous characters; possibly related to the Heliometrinae). 



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

 a central mouth, and prominent sacculi; the cirri, though slender, are not excessively 

 so; there are no carinate processes on the basal segments of the proximal pinnules; 

 terminal combs occur only on the pinnules of the first pair, PI and P a , from one or 

 both of which they may be absent; the combs usually arise about, or within, the 

 proximal third of the pinnule and are composed of exceptionally large rounded teeth 

 which usually much exceed in height the lateral diameter of the segments which 

 bear them; the fourth-seventh brachials bear prominent spinous median knobs or 

 keels; usually one or more of the earlier segments of P t are twice as long as broad, or 

 even longer. 



Geographical range. From Key West, Fla., to Cape Lookout, N. C. 



Bathymetrical range. From 14 to 366 (?411) meters. 



Thermal range. Two records, 11.11 and 27 C. 



Remarks. The genus Comatonia is a most extraordinary type and, except for 

 the enormous comb on the oral pinnules, can scarcely be said to resemble the other 

 comasterids in any particular. But neither does it, except superficially, resemble any 

 other type of comatulid. 



Dr. Torsten Gisle"n has pointed out its anomalous characters and has suggested 

 a possible relation to the subfamily Heliometrinae (Antedonidae). But the perfectly 

 typical indeed exaggerated comasterid terminal combs seem to me to make its 

 systematic position clear, expecially when ComatUia and Microcomatula, also curiously 

 aberrant forms, are taken into consideration. 



COMATONIA CRISTATA (Hartlaub) 



Plate 6, Figures 17-20 

 [See also vol. 1, pt. 2, fig. 790 (adambulacral deposits), p. 372] 



Anledon, sp. P. H. CARPENTER, Bull. Mus. Comp. Zool., vol 9, No. 4, 1881, p. 155 (distinguished by 

 having enormous lancetlike processes on the lower joints of its oral pinnules; found among 

 the large number of individuals of A. hagenii from the Florida Straits). 



Actinometra crislata HARTLAUB, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, pp. 280, 413 (listed) ; 

 pp. 473-475 (?locality; detailed description); pi. 10, figs. 1-5; pi. 15, figs. 10, 11. A. H. CLARK, 

 Unstalked Crinoids of the Siboga Exped., 1918, p. 4, footnote (type of Comatonia; off Cape 

 Lookout, N. C., 7% fathoms; near Key West, 120 and 132 fathoms. 



Comatonia cristata A. H. CLARK, Journ. Washington Acad. Sci., vol. 6, No. 5, 1916, p. 1 15 (range; 

 only species in the genus); The Danish /nffo//-Exped., vol. 4, No. 5, Crinoidea, 1923, p. 39 

 (range). 



Diagnostic features. 1 This is a small and delicate species with slender arms not 

 more than 50 mm. in length; the cirri are about XL, 14-17, about 13 mm. long, the 

 peripheral cirri being markedly longer and stouter than the apical, an unusual con- 

 dition in the Comasteridae. 

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