TRUE] REMAINS OF FOSSIL CETACEANS 457 



median line instead of flat, as in crassangulum, and the two rows 

 are closely approximated anteriorly. It does not seem to me quite 

 certain that the species caitalicitlatits Meyer, planus Gervais, dcpcrcti 

 Paquier, and dationum Gervais 1 are identical with sulcatus, as Dr. 

 Abel believes. The mandible of caniculatus Meyer is of about the 

 same size as that of crassangulum, or is even smaller. The man- 

 dibular alveoli are equal in size and also the septa between them. In 

 caniculatus, however, the inferior mandibular channels appear to be- 

 come deeper and narrower anteriorly, while in crassangulum they 

 become much wider and shallower, and finally disappear altogether. 



In the species planus Gervais the palate is flat, as in crassangulum, 

 but about twice as wide, while the alveoli and septa are equal in size. 

 The dcpcrcti of Paquier appears to resemble sulcatus closely, except 

 in proportions. The anterior mandibular teeth are much larger than 

 in crassangulum and are directed upward rather than outward. The 

 portion of the symphysis between the two rows is much narrower. 



As to dationum Gervais, 2 the angle of the mandibular symphysis 

 is so small that the species should probably be assigned to Acrodelphis 

 rather than to Schizodclphis. The jaw is of about the same size as 

 that of crassangulum, but the teeth are larger and more widely 

 spaced. 



As already mentioned (p. 450), Cope, in 1867, when treating of the 

 genus Priscodclphiiuis, remarked, "Delphinus canaliculatus von 

 Meyer, from the Swiss Tertiary, appears to belong to it (Palaeonto- 

 graphia, 1856, p. 44)". Von Meyer's species belongs to the genus 

 Schizodclpliis, 3 and Cope's statement amounts, therefore, to a pro- 

 visional introduction of the genus ScJiizodclphis into the North 

 America fossil fauna. Should his surmise be confirmed, the name 

 PriscodelpJiiwus (1852) would supplant Scliizodelphis for both Euro- 

 pean and American species. It is not clear on what ground Cope 

 based his opinion, as S. canaliculatus was described from mandibles, 

 and no mandibles of Priscodclphiiuis were known. To a certain 

 extent he was probably influenced by an examination of the beak 

 from Cumberland County, New Jersey, which is mentioned by Leidy 

 (see p. 451) as probably representing Priscodelphinus grandcczms. 

 This beak, which was figured by Mr. Case in 1904, i is still pre- 

 served in the Academy of Natural Sciences of Philadelphia. Its 



1 In part, Zool. et Pal. Frang., ed. 2, 1859, pi. 83, figs. 1, 2. 

 ' Op. cit., Osteogr. des Cet, pi. 57, fig. 11. 



3 It is made a synonym of S. sulcatus (Gervais) by Dr. Abel, but may be a 

 separate species. 



4 Report of Maryland Geological Survey, Miocene, pi. 15, fig. 1. 



