OPHIOGLYPHA SINENSIS. 13 



Description of a Sp< eimen. — Diameter of disk. 9 mm ' ; from outer corner 

 of mouth-slit to outer side of opposite mouth-shield. 4.2" 11 "' ; distance 

 from outer side of mouth-shield to point of innermost mouth-papilla, 

 to that between outer corners of mouth-slits. 2:2; width of arm. 

 1.4 mm . Mouth-papillaj, six to each angle, whereof the two outer ones 

 on each side are thin and triangular, and the innermost is stouter and 

 more elongated, approaching the form of the teeth, which are four in 

 number, stunt, and formed like a blunt spear-head. Mouth-shields 

 large, - lyre-shaped," that is to say, bounded by a curve without, an 

 angle within, and by re-entering curves on the sides ; so that the inner 

 corners, at the heads of the genital-slits, make little peaks; length to 

 breadth, 1.7 : 1. Side mouth-shields very narrow, meeting w T ithin, and 

 running along inner angle of mouth-shield to its corner, where they run 

 across the head of the genital-slit to the side arm-plate. Under arm- 

 plates small, much wider than long, with an angle within and a cm*ve 

 without. This is their general form, except that the first two or three 

 are squeezed laterally ; length to breadth (Sth plate), .2 : .5, a little 

 way out they become very minute. Side arm-plates large, meeting 

 below along a line longer than the under arm-plate; those within the 

 disk are indented at their juncture, making a little pit. They make a 

 re-entering curve where the tentacle-scale is lixed, and at little peak be- 

 tween it and the under arm-plate. Upper arm-plates strongly arched, 

 wider without than within ; bounded by straight lines on the sides and 

 by a curve without ; length to breadth (8th plate), .G : .8. Disk covered 

 with larger and smaller irregular scales, among which may be seen the 

 larger, round, primary plates. Radial-shields pear-seed shape, nearly or 

 quite touching without : length to breadth, 1.3 : 1. Radial-scales carry- 

 ing a close comb of rounded tapering papillaB, in form like the arm- 

 spines, which grow smaller as they pass below the disk and end in a 

 row of fine grains, midway the genital-slit. Arm-spines, three, slender, 

 rounded, regularly tapering, not quite so long as the joint ; length to that 

 of under arm-plate (8th joint), .8. .7, .7 : .2. Tentacle-scales thin and 

 nearly round. On the first pair of great pores, three or four on each 

 side ; on the second and third, three on one side and two on the other ; 

 on the fourth, two on one side and one on the other. The next four 

 or five pores have one large scale, and a very small one, which last 

 stands on the side arm-plate. Color, in alcohol: straw yellow. 



Collected, almost without doubt, at Hong Kong, by Captain W. II. 

 A. Putnam. 



Variations. — All the specimens had broken arms, but by their char- 

 acter they had probably about the proportions of 0. Sarm, >;\y a length 

 of three or four times the diameter of the disk. There were two 

 specimens in which the side mouth-shields were broader; the pit- on 



