BRITISH FOSSILS. 



Decade IX. Plate I. 

 COSMOLEPIS. Gen. Nov. 



[Genus COSMOLEPIS. Agassiz. (Sub-kingdom Vertebrata. Class Pisces. 

 Order Goniolepidoti. Family Sauroidei. Sub-family Sauroidei homocerci. 1st group, 

 tail forked.) Body oval. Head small. Scales thick, small, numerous, and rhomboidal ; 

 sculptured on their surfaces. Pectoral fins large ; ventral fins near the pectorals ; dorsal 

 fin in advance of the median line, over the interspace between the ventral and anal fins ; 

 anal fin extended ; caudal fin large, springing from a broad pedicle.] 



Species Unica. Cosmolepis Egertoni. Agassiz, MS. Morris^ Cat. 

 Brit. Foss., 1854. 



In the generic characters here given, I have endeavoured to 

 express those features which distinguish Cosmolepis from the 

 several sauroid genera with which it has affinities in other respects. 

 The form of the trunk corresponds with that of Pachycormus, the 

 advanced position of the dorsal fin with Caturus, the extent of the 

 anal fin with Sauropsis, and the character of the scales and caudal 

 fin with Oxygnathus. It differs from Pachycormus and Caturus 

 in having thick sculptured scales, in the form of the tail and in the 

 proportions of the anal fin ; from the former in the position of 

 the dorsal fin. It differs from Sauropsis and Oxygnathus in the 

 greater depth of the trunk in relation to its length, and in the 

 arrangement of the locomotive organs ; and from all in the forward 

 position of the ventral fins. The genus was established by Professor 

 Agassiz, immediately before his departure for America, from the 

 examination of a single specimen belonging to Lord Enniskillen, 

 and found in the lias quarries at Barrow-on-Soar. A second spe- 

 cimen has been found since (now in my possession), which agrees in 

 generic and specific details with the original. 



Description. — The anterior half of the head is deficient in both 

 specimens ; in other respects they are in a good state of preservation. 

 The type specimen is selected for the general description, as being 

 the most perfect, but some of the details are derived from the last 

 found specimen. The form of the body is elliptic, the dorsal and 

 [IX. i.] 9 B 



