OPHIURANS OF UNITED STATES NATIONAL MUSEUM. 95 



0. vepratica was established by him for four specimens, two of which are young 

 ones; in the type, the diameter of the disk measured 6.5 mm.; the specimens from 

 the Albatross are generally a little larger and the diameters of their disks usually 

 range between 7 and 8 mm. 



Lyman characterized 0. vepratica, among other things, by the presence on the 

 upper face of the disk of granules with which a few short spines were mixed, and 

 these spines were represented by him on various drawings (78, pi. 10, fig. 246, and 

 82, pi. 13, fig. 8) ; now, among the many hundreds of specimens which I have been 

 able to examine, I have not found a single one bearing spines on the upper face of 

 the disk. In all of them the disk offers an extremely regular covering of granules 

 which are somewhat irregular in thickness, but all of which reach the same height; 

 these granules are large and elongated and their shape is that of an extremely short 

 cylinder, ending in a small swollen head; this head is covered with extremely small, 

 short, pointed, and dense spinules, which are hardly visible except through the 

 microscope. The radial shields are small, in the shape of very much elongated 

 and narrow triangles, widely separated. All these details can be ascertained on 

 dry specimens only, on which may easily be seen the limits of the upper plates of 

 the disk, these plates carrying each a very short cylindrical stump. 



The upper face of the disk thus shows some characters and an appearance 

 which are fairly different from what Lyman pointed out, and I should never have 

 been so daring as to refer my specimens to 0. vepratica had not the Jardin des 

 Plantes possessed a specimen of that species from the dredgings of the Blake and 

 determined by Lyman, the examination of which enabled me to fix my own deter- 

 mination. This example, though very small, since the diameter of his disk is only 

 4 mm., is altogether in conformity with the specimens from the Albatross; especially 

 is the upper face completely deprived of spines and bears only some elongated 

 granules which are very rough, ending in very conspicuous spinules, which are 

 absolutely identical with those observed by me on my own specimens. 



The mouth pieces are disposed as indicated by Lyman. The under brachial 

 plates are very large and wide; they are first wider than long and then they become 

 as long as wide; a few concentric stria? are seen on their surface as well as on that 

 of the lateral plates. The tentacular scale is large and fairly wide, somewhat rough; 

 there are sometimes two such scales on the tentacular pores of the first pair, and 

 in this case the external scale is smaller than the internal one. The spines amount 

 to eight at the base of the arms; Lyman indicates only seven of them in his descrip- 

 tion, but on his drawing (82, pi. 13, fig. 9) he reproduced eight; these spines seem 

 to be smooth when seen with the naked eye, but through the microscope they 

 appear covered with numerous denticulations which are exceedingly small, pointed, 

 short, and dense. The two rows of spines are more approximated dorsally than 

 represented by Lyman. 



0. vepratica was found by the Challenger at latitude 28 S. and longitude 

 177 W., at a depth of 600 fathoms, near the Fiji Islands. It was afterwards met 

 with by the Blake in several localities of the West Indies, near Nevis Island, 

 Barbados, Martinique, St. Vincent, and Grenada, in depths of 291-476 fathoms, 

 as well as at station 41 in 860 fathoms. 



Lyman has done no more than cite the occurrence at the various above- 

 mentioned localities without adding anything to his original description. 



