2 PROCEEDINGS OF THE NATIONAL. MUSEUM vol.66 



Besides these skulls, several mandibles and numerous vertebrae, 

 ribs, and limb bones, whicli are referable with little doubt to this 

 genus have been obtained at this and other points in Maryland and 

 Virginia. As Professor Abel's* promised description of the verte- 

 brae, and other parts of the skeleton of the European species of the 

 genus Eurhinodel'phis has not yet appeared, a full comparison of 

 these parts is not possible at present, but from such figures and 

 records as have been published it is evident that a few of the Ameri- 

 can forms can be safely referred to the genus Eurhinodel'phis^ includ- 

 ing not only those obtained from the Calvert cliffs, but also some of 

 the vertebrae and other parts of skeletons described during the last 

 half of the nineteenth century by Leidy, Cope, and other American 

 writers. From the vertebrae at present available for study, two 

 courses present themselves for the treatment of the material. One 

 can follow Abel and state that there is a wide range of individual 

 variation in corresponding vertebrae or adopt the view of Leidy and 

 Cope that each type represents a different species. 



The types of the American species already described by Cope and 

 Leidy, under the names of Priscodelphinus, Ixacanthus, Delphinap- 

 terus, Tretosphys, and Belosphys, the majority of which are in the 

 Academy of Natural Sciences of Philadelphia, necessarily demand at- 

 tention. Since these latter consist almost exclusively of vertebrae, 

 the question of generic and specific allocation is still an extremely 

 difficult one. Many years ago Du Bus^ attempted to meet this diffi- 

 culty by assigning certain European forms to the American genus 

 Priscodelphinits, but his material consisted entirely of skulls, while 

 the various American species were described exclusively from verte- 

 brae. This association did not, therefore, remove the difficulty but 

 rather increased it. It is, of course, probable that the same species 

 frequented both the European and the American shores of the 

 Miocene ocean, but this can not be taken for granted, for it is known 

 that certain existing species of porpoises are peculiar to European 

 waters and others to American waters. Until further material is 

 obtained at the type locality for Priscodelphinus harlini^ some un- 

 certainty will exist as to the proper allocation of this genus. An im- 

 perfect posterior dorsal vertebra represents all that is definitely 

 known concerning the type species of this genus. Leidy reports that 



* Abel, O., Presentation, avec explications Justiflcatives, d'une reconstruction de 

 rEurhinodelpliis, Dauphin longirostre du BoId6rien des environs d'Anvers, Bulletin 

 Soci6t6 de Beige de G^ologie, Paleont., et d'llydrol, Bnixelles, vol. 20, I'roces Verbal, 

 pp. 163-166, 1906 ; Cetaceenstudien. I. Mitteilung : Das Skelett von Eurhinodelphls 

 Cocheteuxi aus dem Obermiozan von Antwerpen, Sitzungsber. K. Akad. Wiss. mathem.- 

 natunv. Kl., Wien, vol. 118, pt. 1, pp. 241-253, pi., March, 1909. 



* Du Bus, B., Mammif^res nouveaux du Crag d'Anvers, Bull. Acad. Eoy. Soc. Belglque, 

 Bruxelles, ser. 2, vol. 34, p. 492, 1872. 



« Leidy, J., I'roc. Acad. Nat. Sci. Philadelphia, vol. 5, pp. 326-327, 1851 [figured by 

 Harlan, R., Journ. Acad. Nat. Sci. Philadelphia, ser. 1, vol.4, p. 232, pi. 14, fig. 1, 1824.] 



