ON THE DERMAL AKMOUR OF JACARE AND CAIMAN 291 
Genus 4. CROCODILUS. 
The teeth are always strong and very unequal, the strongest in 
the upper jaw being the tenth. The mandibular symphysis does not 
extend beyond the level of the sixth tooth. There are usually six 
cervical scutes, in two rows, or forming a rhomb, and separated by a 
distinct interval from the tergal scutes. There are 18 or 19 teeth 
above, and 15 below, on each side. 
1. Crocodilus vulgaris. 
As Cuvier has remarked, it is extremely difficult to find good 
distinctive characters for all the species of this genus. My first 
difficulty was to ascertain the precise characters of that species which 
has been misnamed wz/garzs, inasmuch as I could find neither in the 
British Museum, nor in the Museum of the Royal College of Surgeons, 
any authentic skeleton or skull of this, the so-called Nilotic Crocodile. 
This difficuity subsisted up to the time that the chief statements con- 
tained in the present essay were laid before the Linnean Society ; but 
since then I have been enabled, by Dr. Gray’s permission, to examine 
the skull of a small stuffed specimen, brought to this country 
from Egypt by Sir Gardner Wilkinson, and to study the splendid 
entire skeleton of a Crocodilus vulgaris in the Christchurch Museum 
at Oxford, presented to that Institution by the gentleman who shot 
it on the Nile, and set up with great care under the auspices of my 
friend Dr. Rolleston, Lee’s Reader in Anatomy and Curator of the 
Museum. Fortunately the entire skin has been preserved; so that 
this is the most complete record of the hard parts of any indi- 
vidual crocodile with which I am acquainted, besides being, so 
far as I am aware, the only authentic entire skeleton of Crocodilus 
vulgaris in this country. I subjoin the chief points of interest which 
I noted in my brief examination of this valuable specimen :— 
Inches. 
The fotal length of therskeleton 18 w.ccicaeces a. asomsancnveaninconsinesa os 114 
#4 a soo ASKOUDUMS. seare aeigtgairemegioneia nelaste walematrcntociee vaigeelct ndion 16 
Between the outer edges of the posterior ends of the quadrate bones 8} 
From the snout to the middle of the canine notch ............ sees 2# 
Transverse diameter of snout opposite roth tooth .............. 4 
Leon ANS: OF OPDIb vi tac.psvasaciuca dts SeceGietess Saninee seis edinee iy oe ae 24 
Short :axi8 GF OFC ip cmmedescsinw nada rad taaledcucommanaanagRetenninwedioaddte 13 
Interorbital space opposite the middle of the orbit ..... 0.00... 1} 
Anterior edge of the orbit from end of snout.......2. -..eeeeeeeeee ceeee 103 
