16 



( LTALOGUE OF SHIELD KI'ITII ES. 



Baton behind the maxillary bones; in the wider specimen 

 it is much more produced behind than in the other. 



1 havo examined and compared with care specimens of 

 different ogee from North Africa near the Nile, from West 

 AtV: S igal and Gaboon, South Africa al the Cape 



of G i Hope and Natal, and a Bpeoimen brought from 



' tral Africa bj Dr. Baikie; and although thej each ex- 

 hibitcd certain peonliaril ee, yet 1 believe, as far as the 

 [mens at my command enable me to form a judgment, 

 that they all belong to a sin. is which is generally 



distributed over the African continent. 



At ti me, from the slight differences which the 



imens from the different localities do exhibit, I should 



not he surprised, it' we had a complete series of perfect 



mens and of skulls of different ages from each locality, 



to find that tl sufficient differences between them 



how that each locality has a special local variety or, 



perhaps, species; hut unfortunately there is not in the 



British Museum, or in the other museums and collections 



lich 1 have access, such a series : all the specimens 



from the Cape of Good Hope and West Africa seem to he 



cither in the adult or very young state, while those from 



the other localities are either very young or of an inter- 



ite age. On the other hand, the scries of specimens 



from the same locality, as from S. Africa for example, 



ice we have most specimens, exhibit variations among 



themselves quite as great as between the specimens from 



various parts of Africa. It is therefore more safe to re- 



. them all as one species. 



The Bpecies grow to a large size ; we have a specimen 

 from the Nile and some from the Cape of Good Hope in 

 the British Museum which are nearly 15 feet long. 



The skulls which seem to belong to larger specimens 

 often reach the length of 24 or 25 inches. 



The history of the Xile Crocodile is given in great detail 

 in the tilth volume of Cuvier's ' Recherches sur les Osse- 

 mens Fossiles.' v. p. 43. 



G St.-Hilaire, in his 'Essay on the Crocodiles of 



Egj ". separated the Egyptian specimens into two species, 

 under the name of Croeodilus lacunosus and C. marginatus. 

 In the • Aimales du Museum,' vol. x. p. 83, he described a 

 third, under the name of C. suchus. Professor Owen has 

 figured the skull of a Crocodile, from an Egyptian mummy, 

 under the uame of <'. .<»i7/»s, Geoff., in the 'Monograph of 

 the Fossil Reptilia of the London Clay,' published by the 

 Pais Ideal Society, 1850, t. 1. f. 2. I do not see 



how it differs from the Crocodiles at present found in the 

 Xile. See also Huxley, Journ. Proc. Linn. See. iv. p. 1 5. 



In the 'Catalogue of Tortoises and Crocodiles,' p. Gl, I 



separated the adult < ape ( Irooodiles from (lie North-African 

 Bpeoimens, under the name of ('. marginatus, because the 

 head is not so narrow ; but it is to bo observed that most 

 of the North-African specimens with which I had com- 

 pared them were of small size, and consequently had the 

 bead less developed. 



I>r. liaikie described the Crocodile of Central Africa, 

 found in the river Ewora and Binue(or Niger and Twedda) 



under the name of Croeodilus hi 'inn iisis ; it is of a dark 



green colour, and lives on the mud-banks or swimming in 



the fixers. 



Mr. Cope ('Proceedings of the Academy of Natural 

 Sciences of Philadelphia' for 1850, p. 29G) regards the 

 Crocodile of Equatorial Western Africa (Ogobai) as the 

 Croeodilus marginatus of Geoffrey. 



Dr. A. Smith, referring the Cape specimens to Croeodilus 

 marginatus, observes, "they are occasionally found in the 

 rivers west of Port Natal, but more abundantly in those 

 to the eastward and northward, and occur in such num- 

 bers in the rivers in a district north of Kurrichane, between 

 24° and 22° south latitude, that the natives who used to 

 reside there were known by the appellation Baquana = t}ie 

 people of the Crocodile." — Zool. South Africa, Appendix, 

 p. 2, 1845. 



MM. Dumeril and Bibron, in their ' Erpe'tologie Gene- 

 rale,' iv. p. 104, divided their Croeodilus vulgaris into four 

 varieties, thus : — 



Var. a. The Croeodilus vulgaris of Geoffrey, from North 

 Africa, Egypt, and the Nile. 



Var. 5. Croeodilus palustris, Lesson, described from a 

 specimen sent from the Ganges by M. Duvaucel, and from 

 the coast of Malabar by M. Dussumier. 



Var. c. The Croeodilus marginatus, I. Geoffrey, from 

 North Egypt and the Cape of Good Hope. 



Var. d. The Crocodile verd of Adanson, from the Nile, 

 the Niger, and Senegal. 



There is no doubt that vars. a, c, and d are true Cro- 

 codiles, and are what is considered in this essay to be the 

 Croeodilus vulgaris of Africa. Var. b, on the other hand, 

 does not belong to the same genus. I have not the slightest 

 doubt this variety is founded on young and half-grown 

 specimens of Bombifrons indieus, most distinct from Croeo- 

 dilus vulgaris by the form of the head and the structure 

 of the skull, as MM. Dumeril and Bibron would have 

 found if they had examined any of the twelve specimens 

 which they say- they procured. They have named the 

 adult specimen in the Paris Museum C. hiporcatus. 



In the ' Ann. & Mag. of Natural History,' vol. xviii. t. 7, 

 Dr. Falconer figures the skull of a Crocodile under the 



