CANCEL COAL OF THE "WEST EIDI:s:G OP YOBKSHIBE. 



63 



surface is ornamented by a series 

 of longitudinal striations. On 

 the posterior surface there is a 

 single row of denticles, extending 

 from the apex 2 or 2-5 inches to- 

 wards its base. The denticles are 

 broad at the base along the longi- 

 tudinal axis, their sides are com- 

 pressed, and they terminate ob- 

 tusely ; eight of the denticles and 

 intermediate spaces are contained 

 in the space of 1 inch. The spine 

 is somewhat flattened, and presents 

 an oval section ; but this is pro- 

 bably due to compression, and the 

 spine may originally have been 

 nearly or quite circular. There 

 is an internal cavity, which is ter- 

 minal at the basal extremity and 

 extends almost to the point ; the 

 cavity is central, and large in com- 

 parison to the diameter of the 

 spine. 



Many of the Siluroid and Cy- 

 prinoid fishes of the fresh waters 

 of India bear on the anterior por- 

 tion of the first dorsal fin a bony 

 ray or spine, which is frequently 

 ornamented or armed with a row 

 of denticles along its posterior mar- 

 gin. Among the Cyprinoids may 

 be mentioned the Scliizotliorax ; 

 and in a species of Siluroid, 

 Macrones vittatus^ Bl., kindly sent 

 to me by Mr. Francis Day, and 

 collected by that intrei3id natural- 

 ist in one of the rivers of Northern 

 India, there are one dorsal and 

 two pectoral fins, protected by 

 sjjines ; these present a close ex- 

 ternal resemblance to the spines of 

 Compsacanthus from the Coal- 

 measures of West Yorkshire. The 

 Macrones is a small fish, about 5 

 inches long ; its head is covered 

 with a number of bony plates, 

 whilst the body is devoid of scales. 

 It has two pectoral and two ven- 

 tral fins, and an anterior and pos- 

 terior dorsal fin. All except the 



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