356 REPORT OF NEW JERSEY STATE MUSEUM. 

 Genus Harpurus Forster. 



The Doctor Fishes. 



Harpurus hepatus (Linnaeus). 



Surgeon. 



Distinguished from any of our other fishes by a very sharp 

 knife-edged spine, erectile from a groove. 



Known from our coast only by the record of Dr. Abbott. It 

 is evidently a straggler in the Gulf Stream. 



Acanthurus phlobotomus Abbott, Geol. N. J., 1868, p. 811. 



Sub-Order SCLERODERMI. 



The Hard Skinned Fishes. 



Tropical fishes, mostly inactive, and depending on their tough 

 skin or bony or spinous armature for their protection. 



Key to the families. 



a. First dorsal of III, rarely II spines, first very large, and second locking- 

 it in erection ; scales comparatively large, bony, rough, forming a coat 

 of mail. BALisTiD^. 



aa. First dorsal a single spine, with a rudiment at its base ; scales minute, 

 not bony, edges spinescent, so that surface of body is rough-velvety. 



MONACANTHIDX 



Family BALISTID^. 



The Trigger Fishes. 



Body oblong or ovate, moderately compressed. Eye near occi- 

 put. Mouth small, terminal, low. Jaws short, each with about 

 I series of separate incisor-like teeth. Preorbital very deep. Chin 

 without barbel. Gill-openings small, slit-like, above or in front 

 of pectoral fins and not before eyes. Body covered with rather 

 large rough scales, or scutes of varying form, scutes not forming 

 an immovable carapace. Lateral line obscure or wanting. Post- 



