156 DISCOBOLI. 



0-t. Very young. Greenland. From Hr. Hollboll's Collection. — 



Anterior dorsal fin with six distinct spines. 

 u, V. Half-grown and young. 

 w. Adult : skin. From Gronow's Collection. 

 cc. Half-grown : anatomical preparation. Scotland. 

 _?/. Adult: skeleton. Baltic. Prom Dr. A. Giinther's Collection. 



The oesophagus is wide, and separated from the stomach only by a 

 slight external contraction, the folds of its mucosa passing unin- 

 terruptedly into those of the stomach ; the latter is a large, horseshoe- 

 like, bent sac, the cardiac portion of which is situated along the ver- 

 tebral line, whilst the pyloric is on the ventral side. The pylorus 

 is surrounded by two packets of about fifty appendages of moderate 

 length, some of which are bifurcate. The remainder of the intestinal 

 tractus makes several irregular circumvolutions, and is once and a 

 half as long as the whole fish. The rectum is much wider than the 

 small intestines, and separated from them by a prominent fold of the 

 mucosa. The liver is undivided, triangular, of moderate size, situ- 

 ated on the left side of the stomach. I am unable to detect a gall- 

 bladder*. 



The form of the kidney is subject to some variation : in a Scotch 

 male specimen both halves are symmetrical, their upper ends are thick, 

 and they commence in a deep impression of the diaphragma. They 

 are separated from each other by a thick mass of the muscles of the 

 vertebral column, becoming thinner posteriorly, and are united into 

 one slender cord in the middle of the length of the abdomen. They 

 terminate in a single ureter, before reaching the extremity of the 

 abdomen. 



In a male specimen from the Baltic, examined by myself in Berlin, 

 I found the kidney not symmetrical, the left upper portion having 

 been entirely separated from the remainder of the organ. The right 

 and left upper portions were obtusely pointed superiorly, the extre- 

 mities being imbedded in a capsule formed by the diaphragma. 



The urine -bladder is rather large ; the testicles are entirely sepa- 

 rated. The external openings of the intestines and urogenital organs 

 are very close together, in a fold of the skin. 



Skeleton. — The bones of Cydopterus are distinguished by the small 

 quantity of calcareous salts deposited in them : the latter form thin 

 lamellae in each of the bones, and the interspaces between these layers 

 are filled with a soft gelatinous substance which is soon dried up, so 

 that the bones of the skull shrink together to a shapeless massf. In a 

 fish with the bones ^o incompletely ossified and semimembranaceous, 

 it is often impossible to find the sutures between them. The crown 

 of the head is broad, and the interorbital space of scarcely less width. 

 The orbital edge of the frontal bones is prominent, forming a roof 



* Stannius ( Vergl. Anat. Fische. p. 203) describes the gall-bladder as small 

 and roundish, and accuses Prof. Owen, who has denied its presence, of an error. 

 The specimen which I have examined is from the Scotch coast; that examined 

 by Prof. Owen is probably British also. It may be that individuals of the 

 same species of fishes vary in this respect. 



t These skeletons, therefore, should be preserved in spirits. 



