2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 9I 



Diagnosis. — A genus of Ganeriidae in which the abactinal plates 

 are arranged in regular contiguous longitudinal rows, with a row of 

 enlarged plates separating the abactinal from the lateral surface of 

 each arm ; the superomarginals are blocklike, but the inferomarginals 

 are greatly produced outward, forming conspicuous stalks projecting 

 diagonally outward from the arm ; there is a single row of contiguous 

 elongated actinal plates ; and the adambulacral plates bear two combs 

 of 3-4 spines, a furrow comb and a similar comb on the outer part 

 of the plates, both diagonally placed. Size small, R up to 12 mm. 

 Form stellate, the arms with rather broadly rounded tips. R = 2.24 

 to 2.4 r. 



Genotype. — Korethraster radians Perrier, 1881. 



AMnities. — The genus Leilaster appears to show the closest affinities 

 with Ganeria, from which, however, it is rather widely separated. 



LEILASTER RADIANS (Perrier) 



Plate I, figs. I, 2 



Korethraster radians E. Perrier, Bull. Mus. Comp. Zool., vol. 9, no. i, p. 12 



(description), June 25, 1881. 

 Lophaster radians E. Perrier, Nouv. arch. mus. d'hist. nat., ser. 2, vol. 6, p. 167 



(listed) ; p. 169 (Blake sta. 292, ofif Barbados, 56 fathoms) ; p. 170 (Blake 



sta. 292 [sic], Havana, 80 fms.) ; 1883. 

 Solaster radians E. Perrier, Nouv. arch. mus. d'hist. nat., ser. 2, vol. 6, p. 184 



(56 fms.) ; pi. 6, figs. 9-1 1 ; 1883. 

 Korethraster hispidus E. Perrier, Nouv. arch. mus. d'hist. nat., ser. 2, vol. 6, 



p. 212 (description of K. radians reprinted; Blake sta. 292, Barbados, 56 



fms.; Blake sta. 000 [sic], Havana, 80 fms.) ; 1883. 



Description of the specimen from the Caroline collection. — A very 

 small specimen with five short, regularly tapering, bluntly pointed 

 arms. The abactinal surface is elevated, and on each arm is bounded 

 on either side by a regular row of elongate and enlarged plates beyond 

 which the sides drop rather sharply down to the flat abactinal surface. 

 The entire animal is covered with a rather thick skin that partially 

 conceals the underlying plates. R = 4.7 mm, r=:2.i mm; R = about 

 2.24 r. 



The rather conspicuous anus is surrounded by three small plates 

 with the center strongly elevated into a rounded boss. About these 

 is a ring of five large interradial plates. These are thick, with the 

 inner ends broadened and swollen, sometimes bilobed. One of these 

 imbricates laterally over those on either side ; another is partly con- 

 cealed by the overlapping of the plates on either side ; the other three 

 overlap the plates on one side and are overlapped by the plate on 



