CROCODILUS AETICEPS. 263 



of C. cataphractus and C. intermedins and to a less degree of C. americanus ; from the 

 two former it is distinguished by the much longer nasals and the very slight expansion 

 of the premaxillary region. In C. americanus also the premaxillary expansion is 

 greater and the snout is rather less elongated. 



Of the long-snouted Eocene Crocodilia previously described, the present species 

 seems to approach most nearly to C. arduini, Zigno *, from the Nummulitic beds of 

 Monte Zuello, near Verona ; but it differs from the latter in the smaller expansion 

 of the premaxillary region, the comparative narrow^ness of the interorbital bar, and 

 the less rounded orbits. Crocodilus spenceri, Bucklandf, w^hich Lydekker J regards as 

 identical with C. arduini, differs in much the same way, but the premaxillary region 

 seems to be still more expanded than in the Italian form, and, so far as can be seen, 

 it differs also in having the premaxillo-maxillary suture on the palate almost transverse. 

 Crocodilus holcensis, Sacco §, from the nearly contemporary Monte Bolca beds, is 

 distinguished from the present species by the fact that the nasals do not extend 

 nearly to the nasal opening and, judging from the figure, by the much wider inter- 

 orbital bar : this latter character may be partly dependent on the age of the individual. 

 Crocodilus vicentinus, Lioy ||, from the same beds, is a wide-snouted form. 



Although no mandible has been found in actual association with the skull of 

 this species, specimens showing a form and dentition such as might be expected 

 to belong to it have been collected. The most nearly perfect of these (C. 10065) is 

 figured on PI. XXII. figs. 2, 2 A ; it is almost complete, wanting only the posterior 

 extremity of the left ramus : the teeth are for the most part in an excellent state of 

 preservation. The symphysial region is comparatively long and narrow, though less 

 so than in C. cataphractus, C. intermedins, C. arduini, and probably also than in 

 C. bolcensis; it reaches back to the level of the sixth tooth, and the splenial does 

 not extend into it. The alveolar border is sinuous, the convex portions bearing 

 the larger teeth, which are the fourth and the tenth and eleventh. The horizontal 

 ramus presents no special peculiarities (see PI. XXII. figs. 2, 2 a). There are fifteen 

 teeth in all ; of these the first is rather large and projects forwards. As already 

 remarked, the fourth and tenth teeth are the largest, the eleventh being a little 

 smaller ; the rest of the teeth are small. As far back as the eleventh all the teeth 

 are sharp with strongly carinated anterior and posterior edges, but behind the eleventh 

 they are blunt and rounded. There are well-marked notches for the reception of the 

 upper teeth behind the second, sixth, and seventh teeth, and shallow pits behind 

 the eleventh and twelfth teeth. 



* Atti E. Accad. Lincei, Memorie, [3a] vol. y. (1880) p. 65, pis. i., ii. 



t Geol. and Mineral, ed. 1 (1836) vol. i. p. 251, vol. ii. p. 36, pi. xxv'. fig. 1. 



+ Catal. Toss. Eept. Brit. Mus. vol. i. 1888, p. 60. 



§ Mem. E. Accad. Sci., Torino, [2] vol. xlv. (1896) p. 77, pi. i. figs. 5 a, 5 5. 



II Atti See. Ital. Sci. Nat. vol. viii. (Milan, 1865) p. 393. 



