REPORT ON THE OPHIUROIDEA. 71 



curved; on either side of the marginal plate are two minute semicircular scales. Radial 

 shields three-sided, longer than broad, joined their entire length ; outer edges with a 

 slight re-entering curve ; interbrachial edges curved ; length to breadth 1*5 : 1*3. Inter- 

 brachial space below filled by a large slightly swollen plate, which is sometimes divided 

 in two by a median line, and by the large, thick, longer than broad genital scales, along 

 the free edge of which are eight or more very minute, short, blunt papillae, extending to 

 upper margin of disk, where they bear an arm comb of two or three papilla?. Three 

 short delicate arm spines about two-thirds the length of a joint, two low on the under 

 surface of the arm, and one well up on its side. Tentacle scales on the first set of pores, 

 two on the interbrachial side and one on the brachial ; beyond this there is only one 

 large scale on the inner side. Colour in alcohol, white. 



The proportionate size of the side arm plates and small number of those of the disk 

 show this to be a young specimen, but its characters are so well marked as to warrant 

 a description ; and its great depth gives it importance. 



Station 158.— March 7, 1874 ; lat. 50° 1' S., long. 123° 4' E. ; 1800 fathoms ; globi- 

 gerina ooze. Station 146.— December 29, 1873 ; lat. 46° 46' S., long. 45° 31' E. ; 1375 

 fathoms ; globigerina ooze. 



Ophioglypha inermis, Lym. (PL VII. figs. 4-6). 



Ophioglyphct inermis, Lym., Bull Mus. Comp. Zool., vol. v., part 7, p. 95, pi. v. figs. 123-125, 

 1878. 



No arm comb, and only a feeble row of grains along the genital opening. Disk 

 covered with thin overlapping scales and very small radial shields. 



Diameter of disk 14 mm. Length of arm about 70 mm. Width of arm close to 

 disk, without spines, 2*5 mm Mouth papillae small, short, pointed, and close set, similar 

 to and continuous with the tentacle scales of the second pair of mouth tentacles. If those 

 be true mouth papillae that stand on the mouth frames, there are eight or ten on either 

 side and a cluster of three somewhat larger on the jaw-plate. Mouth shield broader than 

 long, with very blunt angle inward and outer edge curved ; length to breadth 2 : 2"7. 

 Side mouth shields longer than broad, of nearly equal width, nearly or quite meeting 

 within. First under arm plate small, longer than broad, hexagonal ; second plate broader 

 than long, rounded quadrangular ; beyond this the plates become much broader than 

 long, with sharp angles at the lateral sides, a small peak within, and a rounded angle 

 without. Side arm plates thin, not swollen, just meeting below beyond the fourth under 

 arm plate ; separated above by the large upper arm plates, which are much broader than 

 long, and wider without than within, with lateral sides straight, and outer corners rounded. 



