Fishes. 6991 



from Sir John Richardson's 'Second Supplement to" Yarrell's British 

 Fishes,' a work in which will be found an admirable resume of all that 

 is known of these interesting fishes. The description cited was made 

 from a specimen taken at Cullercoats on the 26th of March, 1849. 



"The fish, though much injured and greatly faded, was fresh and 

 had a uniform silvery gray colour, except a few irregular streaks and 

 dark spots towards the fore part of the body, and these were remains 

 of a bright iridescence about the pectoral fin and head, a blue tint 

 predominating. The body is excessively compressed, like a double- 

 edged sword-blade, its greatest thickness being below the middle, and 

 the dorsal edge is sharper than the ventral one. The total length 

 when the mouth is retracted is twelve feet three inches, and the depth 

 immediately behind the gills eight inches and a half; two feet farther 

 back the greatest depth of eleven inches and a quarter is attained, and 

 at the end of the dorsal fin it has diminished to three. The skin is 

 covered with a silvery matter in which the scales are invisible to the 

 naked eye, but which is easily detached and adheres to anything it 

 comes in contact with. Submitted to the microscope, this nacre was 

 found to consist of scales like those on the wing of a moth. Round 

 the hind border of the operculum there is a broad dusky patch ; a 

 crescentic dark mark exists above the eye, and there are eight or nine 

 narrow obhque streaks on the side, which diminish to mere spots 

 beyond the vent. The lateral line descends gradually from the supra- 

 scapula to within two inches of the ventral profile at the vent, and 

 continues descending as it proceeds to the distal end of the fish. 

 Four flattened ridges, each more than an inch in breadth, reach from 

 the head to the tail above the lateral line, the longest and uppermost 

 commencing near the eye. The skin is studded with numerous bony 

 tubercles not regularly arranged, and in the neighbourhood of the 

 head they are replaced by depressed indurations. On the ventral edge 

 the tubercles are numerous and have hooked tips pointing towards the 

 tail. The head is small, measuring only nine inches to the gill-opening ; 

 the orifice of the mouth is circular, and capable of being protruded 

 two or three inches by the depression of the mandible : the tongue is 

 small, smooth and prominent ; there are no teeth, and the interior of 

 the mouth is black. Gill-plates proportionally large ; preoperculura 

 crescentic, with the lower horn prolonged forwards to the articulation 

 of the mandible ; operculum curved elliptically posteriorly, ending 

 obtusely. Branchiostegals seven. Branchial arches four, with tubercular 

 bristly rakers. Pharyngeal bones above and below furnished with seta- 

 ceous teeth. The dorsal fin extends from between the front of the orbits 



