EEPTILIA. 315 



unequal; the point of the fourth tooth of the lower jaw on each side 

 capable of reception in a pit of the upper jaw. 



Sp. Crocodilus sclerops Guv., Ann. du Mus. x. PI. i, fig. 76, 6, the skull, 

 PI. 1 1, fig. 3, the nuchal shields or scutes, TIEDEMANN, OPPEL u. LIBOSCH. 

 1. 1. Tab. 5, MAXIM. Abb. zur Naturgesch. Brazil. Lief. xii. ; Caiman 

 fissipes SPIX, Champsa fissipes WAGL., FITZINGER and J. NATTERER, 

 Beitrdge zur ndhern Kenntniss der Sud-Amerikanischen AUigatoren, Annalen 

 des Wiener Museums, n. 1839, p. 321, Tab. 22; this species is met with in 

 South America, and attains a length of 8'. Other species also from South 

 America were formerly confounded under the collective name of Sclerops. 

 All the species of this sub-genus are from the western hemisphere ; they 

 occur in higher latitudes than the crocodiles of the eastern hemisphere. 

 Crocodilus lucius Cuv., Crocodilus missisipiensis, DAUD., Cuv. Ann du 

 Mus. 1. 1. PI. i, figs. 8, 15, PI. 2, fig. 4, TIEDEM., OPPEL u. LIBOSCH. Tab. 4, 

 with a flat head, round in front, which attains a length of 14'; lives in 

 North America. 



ft Upper jaw not wider than lower. Fourth tooth of lower jaw on each 

 side received on the emarginate outside of upper jaw. Hind feet palmate. 



Crocodilus Cuv. Teeth unequal. Head gradually narrowed 

 towards the snout. Margins of upper jaw waved (festooned). 



Of this sub-genus of the crocodiles proper most of the species are from 

 the eastern hemisphere. From the western are Crocodilus rhombifer Cuv., 

 TIEDEM., OPPEL u. LIBOSCH. 1. 1. Tab. 10, from Mexico and Cuba, and 

 Crocodilus acutus GEOFFR. Si.-HiL., Ann. du Mus. n. PL 37, fig. i, Cuv. 

 Ann. du Mus. x. PI. i, figs. 3, 14, PI. 2, fig. 5, TIEDEM., OPPEL u. LIBOSCH. 

 1. 1. Tab. 13, from St Domingo. 



Of the species of the old world we notice, in the first place, that earliest 

 known from the Nile, Crocodilus vulgaris Cuv., Ann. du Mus. x. PI. i. 

 figs. 5, 12, PI. 2, fig. 7, WAGL. natiirl. System der Amphib. PL 7, TIEDEM. 

 OPPEL u. LIBOSCH. Tab. 8; with six keeled plates on the upper part of 

 the neck, fowr in the first and two in the hinder row; the large dorsal 

 shields form transverse rows, each consisting of six shields. The nilotic 

 crocodile is now no longer met with in the Delta, but only in Upper 

 Egypt ; in addition in many other parts of Africa, in the Senegal, &c. In 

 the East Indies at the Sunda-islands, &c. is found Crocodilus biporcatus 

 Cuv., Ann. du Mus. x. PL r, figs. 4, 13, 18, 19, PL n. fig. 8, TIEDEM., 

 OPPEL u. LIBOSCH. 1. 1. Tab. 9, with two tuberculated projecting ridges 

 running along the head from the eyes forward. This species attains a 

 length of eighteen feet. In the interior of Borneo the voyager S. MUELLEB 

 discovered a remarkable species, with snout much elongated, which, 

 accordingly, he thought might be regarded as a gavial, Crocodilus Schle- 

 gelii, Tijdschr. voor natuurl. Gesch. en Physiol. v. 1838, bl. 61 87, PL 3; 

 this species is very beautifully figured in the Verh. over de natuurl. Gesch. 

 der Nederl. Overzeesche Bezittingen, Eeptilia, Tab. I. n. (GRAY has lately 

 united this species incorrectly with Crocodilus Journei. Compare on this 



