362 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



Genus HALITYLE Fisher. 



Halityle Fishek, 1913c, p. 211. Type, Halityle reyularis Fishee. 

 Culcitaster H. L. Claek, 1915, p. 144. Type, Culcitaster anamesus Clark. 



Diagnosis. — Differing from Culcita in having the marginal plates 

 visible in the adult, and in having the papulae in very numerous, 

 regularly arranged triangular areas, resembling those of Oreaster, 

 usually in sixes around each primary plate; in having regularly 

 tessellated actinal intermediate areas. Form pentagonal, or pentag- 

 onal-stellate with very short rays ; no spines on any plates except the 

 adambulacral and mouth plates; bivalved and spatulate pedicel- 

 lariae present; end of rays permanently recurved so that the ambu- 

 lacral furrow becomes dorsal at the apex. 



Remarks. — The type-species is of large size and has retained the 

 phanerozoniate character of young Culcita. This feature and the 

 regularly arranged, triangular papular areas generally in sixes, and 

 the very conspicuously, regularly tessellated actinal surface provide 

 a combination of characters not duplicated in either Culcita or 

 Oreaster. 



I think there is little doubt that Culcitaster Clark will have to be 

 merged Avith Halityle. The type is from the coast of West Aus- 

 tralia. It has short rays at the corners of the swollen dispropor- 

 tionately large disk. The regular arrangement of the abactinal plates 

 and papular areas, and the tessellation of the actinal surface are 

 the same as in H. regularis. One important difference, however, is 

 that the marginal plates are concealed except on the terminal third 

 of the ray. Whether this is of gene'ric value can not now be deter- 

 mined. 



I agree with Doctor Clark that it is difficult to understand how so 

 large and conspicuous a form should have so long remained unde- 

 scribed, and like him I have been unable to find anything in the 

 literature which would indicate that European zoologists had ever 

 seen either species. 



As Doctor Clark states, the genus appears to occupy a place be- 

 tween Oreaster and Culcita. 



The names Randasia Gray, Goniodhcus Miiller and Troschel, and 

 Goniodiscides Fisher (for Go7iiodiscus, untenable), do not enter into 

 competition with Halityle, having been founded upon immature 

 specimens of Culcita. 



HALITYLE REGULAKIS Fisher. 



Plate 94, figs. 7, la ; plate 95, fig. 10 ; plate 98, fig. 1 ; plate 99, figs. 1, 2 ; plate 100, 



figs. 1, 2. 



Halityle regularis Fisher, 1913c, p. 211. 

 Diar/nosis. — Differing from the species of Cidcita in having well- 

 defined marginal plates in the fully adult, no tubercles or spines on 



