NATURAL SCIENCES OP PHILADELPHIA. 103 



The anal fin is trapezoidal, higher than long, and under or behind the 

 median rays of the second dorsal. 



The pectoral fins are pointed. The ventral are inserted almost beneath the 

 bases of the pectoral. 



The scales on the body and crown have pectiniforni borders ; those on tho 

 cheeks and opercula are mostly cycloid. 



The lateral line is continued to the end of the caudal fin. 



The inferior pharyngeal bones are triangular, with their basal or posterior 

 margin widest, and provided with a shallow, braced-formed (,-w-^^O emargi- 

 nation, the posterior processes being short and robust. There is a much thick- 

 ened triangular area beneath and behind, the apex of which is continued into 

 a median or sutural carina or elevation, whence the bones decrease in thickness 

 to the margin. From the base of each ascending side of the thickened trian- 

 gular area, a strong compressed process proceeds downwards and outwards, 

 and is nearly at a right angle to an inferior ridge, which terminates at the 

 end of the compressed posterior process of the bone. 



There are three upper pharyngeal bones on each side ; the median is broad 

 and of a curvilinear, triangular or subcircular form ; the anterior and posterior 

 narrow. 



Most of the teeth of the inferior and upper pharyngeal bones of the adult 

 are molar, short, and with truncated or slightly excavated crowns. Only 

 those of the external margins are sometimes cylindro-conic. 



The setcese lamina? of the ceratohyals of the first pair of branchial arches are 

 very short and compressed ; their internal margins are provided with small 

 acute teeth. The dentiferous lamellae of the remaining branchial arches are 

 small and ridge-like, distant and armed with small recurved acute teeth. 



Pseudobranchise are present. 



The pharyngeal bones of the young are separated, but in the adult they 

 become immoveably united, like those of the Pharyngognathi of Miiller. The 

 teeth of the young also incline toward an obtusely cylindro-conic form, but 

 with advancing age, they become more and more robust and truncated, and in 

 the old, almost the entire surfaces of the lower and median upper pharyngeals 

 are paved with short truncated molars. The teeth of the external margins of 

 the median upper pharyngeals generally retain the form which the teeth of 

 the young possessed. 



Genus Haploidonotus (Raf.) 



Aplodinotus Raf., Journal de Physique, de Chemie, et d'Histoire Naturelle, 



vol. lxxxviii. p. 418. June, 1819. 

 Amblodon Raf., Journal de Physique, de Chemie, et d'Histoire Naturelle, 



vol. lxxxviii. p. 421. June, 1819. 



Lower pharyngeal bones described and erroneously attributed to Catasto- 

 moids : 



Amblodon Raf., Ichthyologia Ohiensis, p. 24. 



Corvina sp., Cuvier, Richardson, Kirtland, DeKay, Storer, Giinther, etc. 

 Amblodon Agassiz, American Journal of Science and Art, ser. ii. vol. xvii. p. 

 307. 

 " sp. Girard, Report of Explorations and Surveys for Pacific Railroad 



route, vol. x. Fishes, p. 95. 

 Body rather elongated or oblong ; the subdorsal outline declines backwards 

 with scarcely a curve. 



Head oblong ; dorso-nasal profile declining with a slight sigmoidal curve ; 

 snout high and truncated. Eyes mostly anterior. Preoperculum minutely 

 crenulated. Chin covered with simple skin. 



Teeth on a villiform band in each jaw; that of the upper preceded by a 

 row of slightly larger ones. 



1861.] 



