HISTORY OF THE FISHES OF MASSACHUSETTS. 



GENUS VI. ASPIDOPHORUS, LACEP. 



Body octagonal, covered with scaly plates ; head thicker than the body, with points 

 and depressions above, flattened below ; teeth in both jaws only, none on the vomer ; 

 snout with recurved spines ; branchiostegous rays, six ; body tapering to the tail ; one 

 or two dorsal fins distinct. 



ASPIDOPHORUS MONOPTERYGIUS, Cuv. 

 The Aspidophore. 

 (PLATE VIII. FIG. 1.) 



Cotlus monopterygius, BLOCK, 178. 



" " Single-firmed Butt-head, SHAW, Gen. Zool., iv. p. 265. 



L'Jlspidopltore & une settle dorsale, Jigonus monopterygius, BL., SCHN. 

 Aspidophoroide Tranquebar, LACEP., Cov. et VAL., iv. p. 224 ; vi. p. 554. 



Cotttis (Aspidophorus) monopterygius, CUT., Aspidophore with one dorsal, RICH., Fauna Boreal. Americ., in. p. 50. 

 Jlspidophoroides monopterygius, Bull-head, STOKER, Report, p. 22, pi. 1, fig. 1. 



" Cuv., Regne Animal, ed. VAL., pi. 21, fig. 3. 



Jlspidophorta monopterygius, American Aspidophore, 1 IKKAV, Report, p. 62, pi. 2, fig. 6. 



" " STOKER, Mem. Araer. Acad., New Series, 11. p. 309. 



" " STOKER, Synopsis, p. 57. 



Color. Above, a light brown, with six indistinct transverse black bands extending 

 from the head to the tail ; those upon the anterior portion of the body the broader. 

 Beneath lighter. 



Description. Body elongated, gradually tapering to the tail ; divided longitudinally 

 by eight rows of scaly plates. Those which are situated just back of the head are 

 much the largest. Above, from just back of the eyes to the dorsal fin, are two rows 

 of these plates ; two rows on each side for some distance, and two rows beneath ; 

 making the fish anterior to the dorsal fin octagonal, and posterior to that fin, 

 hexagonal. The angles of the large scales upon the back form prominent ridges, and 

 between them is thus formed a groove, which extends from the snout between the orbits 

 of the eyes to the posterior extremity of the dorsal fin. Back of this fin is seen a 

 dorsal ridge, instead of the furrow, which is continued to the tail. 



The length of the head is equal to about one seventh the entire length of the body ; 

 width of head less than that of body. The whole head is bony ; the eyes are very 

 large ; the orbitar bones prominent. The snout has two recurved spines at its ex- 

 tremity, and a third and smaller one back of them, curving forwards. Mouth small ; 

 numerous minute teeth are observed in both jaws. 



The dorsal fin is situated upon the posterior half of the body, at the extreme 

 portion of the dorsal furrow. 



