296 ON THE DERMAL ARMOUR OF JACARE AND CAIMAN 
3. Crocodilus Americanus (acutius, Cuv.) 
has the slenderness of snout (even more marked) and the form of 
the premaxillo-maxillary suture of the preceding species; but it is 
at once distinguished from this and all other Crocodiles (except 
C. rhombifer) by the marked longitudinal and transverse convexity 
of the middle of the face, which gives the profile a totally different 
aspect from that of the other species, which are flat or concave in 
this region. 
4. Crocodilus Journet 
is another unmistakably distinct and very remarkable species. The 
descriptions and figures given by Graves, Bory de St. Vincent, and 
Duméril and Bibron, of the unique specimen of this Crocodile in the 
Bordeaux Museum, would alone have compelled me to differ entirely 
from the view taken by Dr. Gray of the affinities of this species. 
These observers agree in stating that Crocodilus Journe? has six 
cervical scutes, arranged as in the other Crocodiles, and, as Graves 
says, “ separated by an interval of four inches” from the commence- 
ment of the tergal scutes, whence it is obviously impossible that it 
can be a AZecestops. But, in addition to this, I had the good fortune 
to find among the recent additions to that excellent osteological 
collection which Dr. Gray has gradually formed at the British 
Museum, the skull of a Crocodile obtained from a dealer in Paris, 
and labelled by him “Croc. de l’Orinoke.” I at first imagined this 
Crocodile to be a /ectstops; but on careful investigation it turned 
out to be no other than the skull of a Crocodtlus Journez, somewhat 
larger than the Bordeaux specimen, but as the subjoined measure- 
ments will prove, agreeing with it in all its proportions :— 
Length from end of snout to end of ossa quadrata ............00... a 
Breadth between outer margins of ossa quadrata oo... 92 
ee at the level of the anterior margins of the orbits......... 53 
jo Jat EN@ACS Eh: TOGEN Ass. iraos icon csdaeonsane ncaa ianmencdainentany 4 
ae AL UE GN OF Te BSHOUE sci csacccsemartansnerareeraeasw Ge seeek 23 
on Of thesimtérorbital, Space: sz.xassinnbe Gevstigaed ousanemdeawtes 12 
Length of mandibular symphysis ............:0ccccseeenese sees en nen ees 5 
Now Duméril and Bibron expressly state that the length of the 
head of C. /ournet equals 2} times its greatest transverse diameter, 
that the width of the jaws at the anterior margins of the orbit equals 
one-fourth the length of the head, and that at the tenth tooth it equals 
one-sixth the length of the head ; and these are as nearly as possible, 
