NATURAL SCIENCES OF PHILADELPHIA. 495 



Notorhynchus maculatus Ayres. 



Notorhynchus maculatus Ayres, Proc. California Academy of Natural Sci- 

 ences, vol. i. p. 72, 1855. 

 Heptanchus maculatus Girard, Explorations and Surveys for a Railroad Route, 

 &c, vol. x. Fishes, p. 367. 

 | 31 + 22 -f 34 -f 3m 



Dent. -| 



6 | 1 

 The first three teeth on each side of the symphysis are on an arch more ad- 

 vanced in front than the others ; they successively increase in size and each 

 has a quadrate bony base from which the enamelled cusp slightly curves 

 outwards and backwards, and whose internal margin is common to it at the 

 base, while the external angle of the latter is more and more produced laterally. 

 The two (or three) succeeding teeth are nearly similar and have a much 

 smaller acute cusp at the outer base of the primary one ; the fifth or outermost 

 of the two bicuspid teeth is wider and much shorter than the preceding, slightly 

 serrated in its ascending margin, and equals in size the next; the succeeding 

 are finely serrated on the internal basal half of the cusp, while the oblique mar- 

 gin on the outer side of the cusp is armed with very oblique, small and sue- 

 cessively decreasing denticles ; the seventh and eighth teeth being alike armed 

 with two or three 6uch denticles directed outwards, while the third is broader 

 with a smaller cusp and an obliquely descending inner margin armed with 

 three or four denticles ; the three succeeding teeth (9 11) are smaller, and 

 the great cusp successively becomes smaller and nearer the centre of the teeth. 

 Behind are nine or ten small, wide tubercular teeth. 



There are six teeth on each side of the lower jaw, uniform in shape, very 

 wide, obliquely declining sideways or outwards, and generally with seven 

 graduated cusps, the first of which is largest and the outermost rudimentary 

 and horizontal. The obliquely ascending inner margin of each tooth is 

 gibbous or curved near the jaw and finely denticulated along most of its edge. 

 The osseous portion is much more developed than the enamelled part and is 

 about twice us wide as high. Next to each corner of the jaw are about nine 

 rudimentary tuberculous teeth. 



Family SPINACOID.E (Owen,) Gill ex Mull, and Henle. 

 Lea Squales partim > ^ . R Animal tome 123 m) lgn 



Squalus S 



Squalidae verae (Spinacini) Bonaparte, Selachorum Tabula Analytica, p. 4, 



1838. 

 Spinaces Mailer and Henle, Systematische Beschreibung der Plagiostomen, p. 



83. 

 Squalidae (Anacantiana) Gray, List of Specimens of Fishes in British Museum. 



Chondropterygii, pp 40, 69. 

 Spinacidse Owen, Comparative Anatomy of the Vertebrated Animals, vol. i. p. 



51, 1846. 

 Spinacoidei Bleeker, Systematis Piscium Naturalis TentameD. 

 Spinacoidae Gill, Analytical Synopsis of the Order of Squali, pp. 29, 31, 38 ; 



ib. in Annals of the Lyceum of Nat. Hist, of N. Y., vol. vii. p. 395, &c. 

 Spinax (genus) Cuvier, Regne Animal, ed. 1, tome ii. 



Body more or less elongated, obtusely trihedral or subcylindrical and fusi- 

 form, gradually tapering behind. 



Scales variable. 



Head depressed, oblong and transversely rounded, or obtusely produced in 

 front, with the snout projecting along the plane of the forehead, and below de- 

 clining backwards to the mouth. Eyes lateral, anterior or submedian, with no 

 nictitating membrane. 



1862.] 



