SYSTEMATIC CATALOGUE OF FISHES. 



337 



north as Massachusetts.* This species was not heretofore recorded from North 

 Carolina, but has recently been taken on several occasions at Beaufort, as follows : 

 In the summer of 1902 one 1.5 inches long at Bird Shoal; in 1903 one 1.75 inches 

 long near the laboratory; and on July 21, 1904, two 2.25 inches long in the harbor. 

 The species rarely exceeds 3 inches in length. 



Family HEPATIDiE. The Surgeon-fishes or Tangs. 



The fishes of this family may easily be recognized by the presence of 1 or 

 2 spinous processes on each side of the narrow caudal peduncle, together with an 

 oblong, much compressed body, with elevated back; short head; small, low, 

 terminal mouth, armed with a single row of narrow teeth in jaws; short maxillary 

 closely united with premaxillary; small, high eye; double nostrils; 4 gill-arches, 

 with rudimentary rakers; gill-membranes attached to isthmus; large pseudo- 

 branchiae; small scales completely covering body and head; complete lateral 

 line; long, narrow, connected pelvic bones; few pyloric coeca; large air-bladder; a 

 single greatly elongated dorsal fin, with spinous part shorter than soft part; anal 

 fin similar to but shorter than dorsal; broad caudal fin with concave margin; 

 and thoracic ventrals with about 5 soft rays preceded by a spine. The family 

 has about 100 members in the warmer regions of the world, most of them belong- 

 ing in the only genus found on the eastern coast of North America. 



Genus HEPATUS Gronow. Surgeon-fishes; Tangs. 



In this genus the armature of the caudal peduncle consists of a single sharp, 



movable spine on each side which fits in a groove and is capable of being extended 



like the blade of a lancet, whence the various common names of these fishes; as 



the species are herbivorous, it is evident the spines, which can inflict a painful 



wound, are employed only for protection. Lateral line arched; scales very fine 



and numerous; dorsal spines 9, anal spines 3; teeth strong and immovable. 



About 6 species known from American waters. Of the 3 species found regularly 



in Florida and as stragglers as far north as Massachusetts, 2 were recently 



detected in North Carolina waters which may thus be distinguished: 



i. Caudal fin slightly concave behind; caudal lobes about equal; about 12 dark vertical bars 



on sides hepatus. 



a. Caudal fin deeply concave behind; upper caudal lobe terminating in a produced filament; no 

 vertical bars on sides '. bahianus. 



{Hepatus, an old name for some European fish.) 



291. HEPATUS HEPATUS (LinnsBUs). 



Surgeon-fish; Tang; Lancet-fish; Doctor-Fish. 



Teuthia hepatus Linnaeus, Systema Naturge, ed. xii, 507, 1766; Carolina. Jordan & Evermann, 1898, 1691, 



Diagnosis. — Body ovate, the depth .4 to .5 length; head contained 3.5 times in total 

 length; superior profile very steep, making an angle of 45° with long axis of body; snout about 

 .6 head; eye .5 snout; dorsal fin of nearly uniform height throughout, the rays ix,25 or 26; anal 

 rays in, 22 to 24; caudal somewhat shorter than head, the lobes of nearly equal length. Color: 



* In a small bay on Marthas Vineyard more than 100 were collected by the writer in the summer and fall 

 of 1900. 



