426 Davis — On the Fossil Fish of the Cretaceous Formations of Scandinavia. 



inter-neural spines are present. Tlie haemal spines are longer than the neural. 

 Attached to them are inter-hsemal bones of great strength ; their anterior and 

 posterior margins are expanded, so that the series form an almost continuous bony 

 mass. The anterior inter-hsemal bones are more numerous than the hsemal 

 spines. There are two, and in the anterior part three, inter-hsemals to one 

 hsemal. The first hsemal and inter-haemal are very thick and strong, and are 

 each of so great a length that they overlap to a considerable extent. The lower 

 extremity of the inter-hsemal is widely expanded, and with a convex curvature 

 extends forward to such an extent as to form an attachment with the styliform 

 process of the post-clavicle and other elements of the scapular arch. With so 

 strong a basis for support, it will naturally be inferred that the anal fin was 

 large, with antei'ior spinous rays, but no trace of the actual fin remains on the 

 specimens under examination. Nearer the caudal fin both the hsemal and neural 

 spines and their auxiliaries become rapidly smaller. The caudal fin is attached by 

 a short peduncle ; the terminal vertebra supports an expanded triangular hypural 

 bone, to which the rays of the tail are attached. Like the dorsal and anal fins, 

 the caudal is not well preserved ; but one specimen shows that the caudal was 

 composed of numerous finely-articulated fin-rays. The ribs were short and 

 attenuated. 



The scapular arch exhibits a peculiar modification, adapting it to the great 

 depth of the body. The upper members of the series are hidden by the overlying 

 bones of the operculum. Immediately behind the extremity of the mandible, the 

 clavicle extends with a gentle curvature backwards and downwards, and at its 

 extremity joins a styliform process of the coracoid. Attached to these bones is 

 the pubic, a large bone, widely expanded at the base, but tapering upwards to a 

 pointed extremity. The clavicle is a strong bone, with an expansion of the upper 

 surface. A very long and slender post-clavicle, its attachment at the upper end 

 hidden by the gill-covers, descends in the form of a styliform process, and assists 

 in giving support to the large pubic bone, to which the ventral fin was doubtless 

 attached, but nothing remains to indicate its size or form. 



Amongst existing fishes the Sun-fish, Lampris hna, is a pelagic fish, which 

 attains to a great size ; it is found commonly near Madeira, and from thence 

 northwards in the Atlantic. Its skeleton exhibits a very large development of the 

 scapular arch, and in many respects it closely resembles the fossil. The clavicle 

 is very long and dilated, and the post-clavicle, slightly expanded at the top, 

 descends in the form of a long styliform bone. Similar characters, but less 

 distinctly specialized, may be observed in the skeleton of Capros aper^ a Mediter- 

 ranean fish, sometimes found on the coasts of England. 



Some of the species of the fossil Gastronemus, most especially G. rhombeus, Ag.,* 



* " Poissons Fossilcs," vol. v., p. 20, pi. ii., figs. 1, 2. 



