ORTHRAGORISCUS. 195 



pricks are smaller (about 1 m.m.) and farther removed 

 from each other, however they are broader there and form 

 wedge-shaped protuberances, the greatest dimension of which 

 runs parallel with the length of the body. Each of these 

 protuberances rests on a polygonal basis , and all these 

 polygonal bases fit together, forming a sort of mosaic. On 

 the dorsal and anal fin the little pricks are arranged in 

 rows parallel with the longitudinal axis of the fin. 



The outer margin of the caudal fin presents dermal 

 ossifications of greater size to the number of eight. These 

 ossicles, the presence of which led Ranzani to set up a 

 separate genus Ozodura^ may be noticed more or less with 

 the four specimens in the Leyden Museum. They are greatest 

 with the two specimens lacking the folded band, viz. that 

 from the Dutch coast and that captured near Leghorn. 

 The size of these ossicles in the margin of the caudal fin 

 may not improbably one day be made one of the charac- 

 teristics of the species. 



Our specimen was of a dusky-brown colour , whilst the 

 part of the body situated underneath the mouth , the eye 

 and the pectoral fin , and in front of the anal fin was of 

 a silvery tinge. It has been carefully mounted and now 

 makes part of the collections of the Leyden Museum. 



Notes from the Leyden Mlixseum, "Vol. XII. 



