NATURAL SCIENCES OF PHILADELPHIA. 499 



that the Artedian name should be reserved for the genus to which it was first 

 restricted by Rafinesque. Blainville's name of Acanthorhinus and Cuvier's of 

 Spinax, consequently were referred to it as synonyme.* 



The genus Squalus as now understood contains four species. 

 Squalus acanthias Linn. Europe generally. 



Squalus americanus Gill = Acanthias kmericanus Storer. Eastern America. 

 Squalus sucklii Gill = Acanthias sucklii Girard. Western America. 

 Squalus blainvillii Gill = Acanthias blanvillii Risso. Mediterranean sea. 



Squalus sucklii Gill. 



Spinax (Acanthias) sucklii Girard, Proc. Academy of Natural Sciences of 



Philadelphia, vol. vii. p. 196, 1854. 

 Acanthias sucklii Girard, Explorations and Surveys for a Railroad Route, &'?., 



vol. x. Fishes, p. 368. 

 Acanthias sucklii Suckley, op. cit., vol. vii. book ii. p. 367. 



Suborder RHIN^E Gill. 

 Squalidae anomalae Bonaparte, Selachorum Tabula Analytica, p. 4, 1838. 



Pectoral fins produced forwards from the anterior basal angle, while the pro- 

 duced portion is separated from the nape by a cleft, in which the branchial 

 apertures are lodged. 



Caudal fin terminal and nearly homocercal, being nearly equally developed 

 above and below the vertebral column. 



This suborder is most nearly allied to the order of Raia?. The rays some- 

 times present as a monstrosity a separation of the pectoral fins by a cleft from 

 the neck somewhat similar to the mode found as a normal feature in the Rhinae. 

 The nominal genus Propterygia of Otto is founded on such a monstrous ex- 

 ample of a species of Rata.] 



Family RHINOIDJE Gill. 



Squatinae Cuvier, Regno Animale. 



Squalidae anomalae (Squatininae) Bonaparte, Selachorum Tabula Analytica, 



1839. 

 Squatinae Midler and Henle, Systematische Beschreibung der Plagiostomen. 

 Raiidae (Squatinae) Swainson, Natural History of Fishes, vol. ii. 1839. 

 Squatinidae Owen, Lectures on Comparative Anatomy, vol. ii. 1844. 

 Squatinoidei, Bleeker, Systematis Piscium Naturalis Tentamen. 

 R.hinoidas Gill, Analytical Synopsis of the Order of Squali, pp. 30,31, 42, 1862. 



Body depressed, rather rapidly diminishing in width behind the ventral fins 

 towards the caudal. 



Scales minute and conical. 



Head depressed, about as wide as long, rapidly decreasing in width to the 

 snout, which is transversely truncated or bluntly rounded. Eye3 on the dorsal 

 surface of the head and near the shout. 



Mouth terminal, transverse. 



Teeth subconical or impressed and slightly trenchant. 



Nostrils terminal, in front of the upper lip. 



Spiracles well developed and behind the eyes, from which they are quite 

 remote. 



Branchial apertures five, approximated, and in front of the base of the 

 pectoral fin, in a cleft between the anterior projection, of which, and the neck 

 they stand. 



* Bonaparte afterwards adopted the name of Spinax for the genus still retained under that ap- 

 pellation, but the genua should be credited to him. 



t See also " >ivta supra una singulare mostruosita di una razza del Dottor F. de Filippi," Ac, in 

 Naovi Acnali delle S< ienze Naturali di Bologna, Feb. 185'2. 



1862.] 



