24 THE DISCOBOLI. 



of carnivorous fishes, — crustaceans, worms, mollu.sks, and fishes, mixed with 

 which more or less of vegetable matter is found in the stomachs of some 

 specimens. 



Anatomy. 



Plate VIII. Figs. 15-17; Plate IX. Pig. 2; Plate X. Fig. B. 



Skeleton. — Much the greater part of this skeleton is soft semi-cartilaginous 

 or gelatinous. A small amount of osseous material exists in thin lamellfe, 

 frequently forming chambers and cavities, upon and around which lies the 

 softer matter. If separated from the soft, the bony substance of a lifteen- 

 inch skeleton weighs less than an ounce. The following description is taken 

 from a specimen having twenty-nine vertebraj, ten of which are without 

 hcemal processes. Near the middle of the body the vertebrse are longer 

 than either the anterior or the posterior, which are about equal in length. 

 Both centra and spines have a bulky appearance ; the former are broader 

 and higher than long. The ultimate centrum bears a pair of broad posteriorly 

 vertically expanded processes, and beneath the lower of these a narrower 

 one, for the base of the caudal. Support for the anterior short rays of the 

 caudal fin is provided by the inflated blade-like spines of the penultimate 

 vertebra. There are but fifteen rays in the fin. All of the vertebral spines 

 incline backward less than forty-five degrees from a vertical. Paraj^ophyses 

 and pleurapophyses are rudimentary, and often imperceptible. 



In the first dorsal tliere are seven rays, all unsegmented, the foremost 

 articulated with the second interneural. Eleven rays, all segmented except 

 the first, occur in the second dorsal. Between the dorsals there are two 

 interneurals that bear no fin rays. The anal fin has eleven raj's, all of which 

 are segmented except tlie first two ; the anterior articulates with an inter- 

 htemal apparently formed by consolidation of two. All of the pectoral rays 

 are segmented ; the upper twelve are branched, the remaining seven are 

 simple, and the lowest one is only about one third of the length of the 

 uppermost. 



Great modifications have been brought about in the pelvis and the 

 ventral fins through the development of the adhesive apparatus. The pubic 

 bones, Plate VIII. Figs. 15 to 17, have extended forward, broadened, and 

 become concave on their lower surfaces as a foundation for the disk. On 

 their inner edges the pubes are in contact, as in the Cottoids; the sharp 

 process reaching directly forward from each is much enlarged, and has a 



