The Four-horned Trunk Fish. 409 



derive their name ; and the only moveable parts are the mouth 

 and lips, a slight border to the slit which constitutes the open- 

 ing of the gills, the fins, and tail with its base or joint. There 

 are real teeth in the jaws ; dorsal and anal fins single and far 

 behind, but no ventrals. As the firmness of the crust does not 

 allow of motion in the body, the flexibility of the joints of the 

 back-bone is unnecessary, and therefore they are united into 

 one. 



The length of the specimen is ten inches, of which the crust 

 measures seven inches and seven-eighths ; the height three 

 inches and three-eights where deepest. The head slopes sud- 

 denly from the eyes. The general form compressed, sharp along 

 the back, flat and wide on the belly ; the section of the shape, 

 therefore, triangular. Eyes, in front, elevated ; and above each 

 a prominent ridge, from which projects forward in a slight 

 curve a stout spine — the pair resembling horns. The snout 

 projects a little, mouth small, lips covering a row of conical 

 teeth — the upper row eight, below six, as far as they can be 

 counted. Grill openings, a perpendicular slit. The back rises 

 in a ridge from between the eyes, and slopes down again 

 toward the dorsal fin ; and about an inch and a half before this 

 fin is a small elevation — the fin itself narrow at the root, but 

 extended. Anal fin further back, nearer the tail than the 

 dorsal. A prominent spine posteriorly on each margin of the 

 flattened under- surface, from which the thin border rises to 

 the place where the moveable caudal portion protrudes from 

 the case in a straight rudder, ending in a caudal fin — the ends 

 of which in this example are injured. The head and body are 

 covered with hexagonal plates, marked in lines round a raised 

 centre. The pectoral fin narrow. Colour, yellowish-brown, 

 but obviously faded. 



