on the Gavial, Tomistoma americana. 237 



Supplementary N~ote oil the Gavial, Tomistoma americana. 



The gavial, Tomistoma americana, described by the writer 

 in 1915, is of special interest from the fact that it is at pres- 

 ent the only known member of this group from the American 

 Cenozoic. Of this form there has been known heretofore only 

 the rostrum which served as the type of the species and a frag- 

 ment of a lower jaw which was regarded as a paratype.* 

 Recently, however, there has been obtained from the same 

 locality and from the same deposit as the type specimens, parts 

 of the lower jaws of ten or twelve individuals, with which is 

 associated a few pieces of upper jaws, dermal plates and a ver- 

 tebra. From the specimens now at hand it is possible to add 

 to the description of the lower jaw. The rostrum which 

 originally served as the type of the species represents, as 

 shown by the specimens now at hand, an individual by no 

 means fully grown. As in the case of the specimens first 

 described, the additional material representing this gavial has 

 been obtained by the Amalgamated Phosphate Company at 

 Brewster, Florida, and has been contributed to the Florida 

 Geological Survey through the general manager of the com- 

 pany, Mr. Anton Schneider. 



The front part of the jaw of this gavial is represented by 

 specimens ISTos. 6158, 5871, 5875, 5876 and 5879 of the Florida 

 Survey collection. The two front teeth of the lower jaw, as ' 

 shown by this new material, incline upward, forward and out- 

 ward, and thus pass between the first and second teeth of the 

 premaxilla which is grooved to receive them. The second 

 mandibular tooth is strongly developed and is separated by a 

 considerable space from the first tooth, and passes between the 

 third and fourth teeth of the upper jaw. The groove in the 

 premaxilla which receives this tooth is more pronounced as 

 shown by specimen No. 6158 in the large individuals of the 

 species than on the specimen which served as the type of the 

 species. Into the broad groove between the first and second 

 lower teeth is received the second and third upper teeth. The 

 space between the first and second lower teeth shows a propor- 

 tionate increase with age, the teeth of the young specimen 

 being about equally spaced. The third lower tooth is small 

 and falls between the fourth and fifth teeth of the premaxilla, 

 being there received in a pit at the outer side of the bone 

 which in old individuals becomes quite pronounced. The 

 fourth mandibular tooth is the largest of the lower jaw and 

 passes into the notch or constriction of the rostrum and hence 

 between the fifth and sixth upper teeth. From the second 

 lower and third upper to the tenth lower and eleventh upper 

 the teeth alternate and interlock, the side of the jaws being 



* This Journal, vol. xl, pp. 135-138, 1915. 



