MOXOGRArH OF JArANESI^ OrHIUROIDEA. 33 



interradial pair is filled by the oral shield, the raadreporite, which 

 is rather large and pear-shaped. The ventral arm plates are very 

 small and grannie-like, except the first and second, which are 

 comparatively large, the first being triangular, with the apex: 

 directed inwards, and the second being fan-shaped with a convex, 

 longest outer side. The lateral arm plates are transversely bar- 

 like, meeting each other in the ventral median lino. Their outer 

 ends are forked, the arm spines arising from the ventral process, 

 while the row of plates which correspond to the dorsal arm plates 

 proceed dorsally from the dorsal process. In the proximal joints 

 of large, sexually mature specimens, each dorsal arm plate is re- 

 presented by a pair of simple, bar-like rows of secondary plates, 

 while in the distal joints, as throughout in smaller specimens, each 

 dorsal plate is represented by a double row of very fine, insignifi- 

 cant scales. In Asteroschema caudatum (Lyman), the structure is 

 essentially similar, but the lateral arm plates are stouter than in 

 the foregoing species, and the ventral arm plates are often divided 

 into two secondary plates. 



Asteronyx lovent Müller & Troschel. 



Asteronyx loveni : MÜLLER & Troschel, Sys. Asfc., 1842, p. 119, PI. X, 

 figs. 3-5; Clark, Bull. U. S. Nat. Mus., LXXV, 1911, p. 285; Döderlein, 

 Abh. Math.-Phys. Kl. K. Bayer. Akad. Wiss., Suppl.-Bd. I, 1911, p. 

 115; Mortensex, Zeitsclir. wiss. Zool., CI, 1912, pp. 264-289, Pis. XIV- 



xvin. 



Astromjx loveni : Lyman, Hep. Challenger, V, 1882, p. 285 ; Kcehler, 

 Ech. lud. Mus. Deep-sea. Opli., p. 74; Kœhler, Exp. Siboga, XLV, Pfc. 

 1, 1904, p. 167. 



One specimen ; Hokkaido, more precise locality unknown. 

 Several specimens, clinging to Isis and other gorgonaceans ; off 

 Misaki. 



