Journal of the Proceedings of the Linnean Society - Vol. 4 / Zoology

VOL. IV. LONDON: LONGMAN, GREEN, LONGMANS AND ROBERTS, AND WILLIAMS AND NORGATE. 1860.
PRINTED BY TAYLOR AND FRANCIS, RED LION COURT, FLEET STREET.
JOURNAL OF THE PROCEEDINGS OF THE LINNEAN SOCIETY OF LONDON.
In the course of a recent investigation into the nature of the singular extinct reptile, Stagonolepis , I was led to inquire somewhat minutely into the character of the exoskeleton, or dermal armour, of the existing Crocodilia . To my surprise, I found that very little detailed information on the subject was to be obtained from the standard repertories of Comparative Anatomy, or even from the special monographs on Crocodilian structure and classification; but I was still more astonished to discover, among whole genera of recent Crocodilia , an exoskeleton possessed of characters such as have been universally supposed to be peculiar to long extinct forms of the order, and whose existence in any recent species has hitherto, so far as I can ascertain, been completely overlooked.
The attempt to discover the limits within which this remarkable exoskeleton is to be found, led me to look, more critically than I had previously done, into the arrangement and specific characterization of the recent Crocodilia . I have thereby arrived at results which, imperfect as they are, may be of service by leading others to inquire into the exact characters of species not at present within my reach; and I therefore propose to preface my account of the peculiarities of the exoskeleton in two of the genera of recent Crocodiles with some remarks on the classification of the group, and with a few notes upon the characters of the species and the limits of the genera.
Everyone is acquainted with the great improvement effected in this branch of Herpetology by Cuvier, who divided the Crocodiles, which he regarded as constituting only a single genus, into the three subgenera Alligatores , Crocodili , and Longirostres . Subsequent writers have admitted these highly natural subdivisions; but there has been a constant tendency to raise their rank. The genus Crocodilus has become the order Crocodilia ; the subgenera Alligatores , &c., have been elevated into families; Dr. Gray has shown that the Alligatores must be divided into three genera, and that there are at least two genera of Crocodili ; and, while one of Cuvier's species of Longirostres has been suppressed, the group is very generally retained with a changed name ( Gavialis ), a very important addition having been made to it in the Crocodilus Schlegelii of Müller and Schlegel.