2 6 NATURAL HISTORY BULLETIN. 



Arm-spines short, usually four to seven or more, (rarely 

 three). Radial shields naked, small, generally divergent, with 

 the distal ends either in contact or somewhat separated by 

 small scales. The disk is usually covered with small naked 

 scales. 



In one group the under side is without scales (/femi/epis) . 

 In a group referred by Lyman to Ophiocnida, the disk is cov- 

 ered with small spinules, but as the mouth-parts and other 

 organs agree with typical Amphiura, it might better be re- 

 garded as a distinct genus, or else as a subgenus of Amphiura. 

 To this I have given the name of Amphiocuida. (See p. )• 



The genus Amphiura, as here adopted, agrees nearly with 

 the typical genus, as restricted by Ljungman in 1867. Mr. 

 Lyman also stated that this should be the typical group, in 

 case the genus were to be divided. This restricted genus 

 still includes over sixty species, with a considerable diversity 

 of structure. The species are found in all seas and in all 

 depths. 



Amphiura grandisquama Lyman. 



Amphiura grandisquama Lyman, Bull. Mus. Comp. Zool., I, p. 

 334, 1869; op. cit., p. 252; Illust. Cat. Mus. Comp. Zool., vol. VIII, 

 pi. V, fig. 65; Voy. Challenger, Zool., V, pp. 124, 143, 1882. 



Several specimens of this species in the collection have 

 been compared with some sent by Mr. Lyman from the Blake 

 Exp. They agree in most respects, but none of those in 

 either lot agree perfectly with the original description. 



The arms are of moderate length, slender and tapered. 

 The disk is covered with very fine, thin, closely imbricated 

 scales, which become still finer below. Radial shields small, 

 longer than wide, inner end widest, adjacent edges nearly 

 straight, outer ones curved; they are nearly in contact at the 

 distal end. divergent proximally. separated by a long wedge- 

 like scale and several smaller ones more proximal; the disk 

 scaling overlaps and conceals more or less of the radial shields, 

 in one case leaving very little exposed. Arm-spines five or 



