309 ON THE DERMAL ARMOUR OF JACARE AND CAIMAN 
as exists tends rather to prove it to be an American species. Thus 
Bory de St. Vincent states that the Bordeaux specimen is ‘ suspected 
to have come from America ;” and, as I have said, the skull in the 
British Museum is labelled “ from the Orinoko.” 
Crocodilus Gravesit ( plantrostris) is supposed by Bory de St. Vin- 
cent to have been brought from the Congo ; but its real origin is not 
known. 
Genus 5. MECISTOPS. 
The cranium is elongated, and the snout slender and Gaviai-like. 
There are eighteen slender and subequal teeth above, and fifteen 
below, on each side. The mandibular symphysis extends back to the 
level of the seventh tooth. The cervical scutes are arranged in two 
transverse rows, each of which contains two scutes; and there is no 
space left between the posterior row and the tergal series. 
This excellent genus, as established by Dr. Gray, includes Cuvier's 
Crocodilus cataphractus (which Dr. Gray considers to be the young of 
a species whose full-grown form was discovered by Mr. Bennett in 
West Africa), Crocodilus Journed and Crocodilus Schlegelitz, As I have 
endeavoured to show, however, C. /owrnez is a true crocodile ; and, as 
I shall point out below, Muller and Schlegel have satisfactorily proved 
C. Schlegelii to be a Gavial. Consequently JZectstops is at present 
represented by only one species, which must be called J. cata- 
phractus if Ml. Bennetti? of Gray is really the adult of the form which 
Cuvier described. 
III. In the family of the GAVIALIDA, the snout is always very 
long and slender; the teeth are for the most part slender, sharp- 
edged and subequal. The two anterior mandibular teeth pass into 
grooves, one of which lies on each side of a beak-like prominence of 
the premaxille, which carries the two anterior upper teeth. The 
canines are received into grooves. The mandibular symphysis extends 
back to at least the fourteenth tooth, and is partly formed by the 
junction of the splenial bones. The premaxillo-maxillary suture is 
always strongly convex backwards. The posterior nares are situated 
more forward than in the Crocodilz. The temporal fosse are large. 
The feet are strongly webbed. The dorsal scutes are not articulated ; 
and there are no ventral scutes. 
I distinguish two genera in this family, Rkynchosuchus and Gavialis. 
Genus 6. RHYNCHOSUCHUS. 
There are twenty teeth above, and eighteen or nineteen below, on 
each side; the mandibular symphysis extends to the fifteenth tooth. 
