THE DISCOBOLI. 35 



unless other specimens show closer approaches than these, they certainly 

 are better kept separate. The depth of body in C. spinosns is contained 

 about two and a quarter times in the length, without the caudal ; the length 

 of the head is less than its height, and is little more than one fourth of the 

 length to the caudal fin. Crown convex, orbit large, less than one third 

 of the length of the head. Mouth moderate, reaching a vertical from 

 the forward margin of the orbit. Teeth small, simple, subcorneal, in a 

 narrow band. On younger examples the anterior dorsal is quite distinct, 

 and does not form a continuous arch with the outline of the back in front 

 of it, as in the Lump, but aged specimens approach the latter more nearly in 

 these respects. Between the two dorsals the space is less than the length 

 of the base of the first. On its posterior margin the caudal is subtruncate, 

 with the angles rounded off. All of the fins have rounded margins. Each 

 of the conical tubercles with which the skin is covered is rough with small 

 projections on its sides and base. Some of the tubercles in diameter of base 

 measure nearly or quite as much as the width of the orbit. The largest 

 appear in a group of eight or nine on the middle of the flank, and in 

 several series from the crown to the base of the second dorsal. One of the 

 large ones stands at each side of the space between the dorsals. A couple 

 of moderate-sized ones are seen in front of the shoulder. Those on the 

 entire caudal region are smaller, as also those below the head and body. 



A young specimen about an inch and a quarter in length has a similar 

 outline in transverse section, as wide as high, is abruptly compressed behind 

 the abdomen, and shows the first dorsal as free and distinct as the second. 

 The back is somewhat arched under the base of the anterior. The inter- 

 orbital space is slightly concave, one fourth wider than the orbit, and one 

 fourth narrower than the disk. Disk nearly one third wider than the orbit. 

 The entire body is covered with irregular-sized spiny tubercles. On the 

 sides of each tubercle the small spines are slender and bristle-like, and their 

 development is comparatively greater than that obtaining among them on 

 older examples. Later in life it is the central portion, or cone, of the tuber- 

 cle that develops, while the lateral outgrowths remain small. On the young 

 individuals the larger scales occupy the spaces behind the pectorals, above 

 the opercles, and at the sides of the first dorsal. Dr. Giinther, 1880, figures 

 some young specimens an inch in length, some with tubercles, others with- 

 out them, and shows the fins to be angular early in life. Our Figures 1-3 

 of Plate XI. were drawn from a specimen taken at Eastport, Maine. Up to 



