have been pressed a little to the southward by the extreme rigor of an Arctic climate, but are still characteristic elements of all boreal faunas. The very few truly tropicopolitan mammalia are either Chiroptera, or marine, or at least aquatic, and have thus exceptional means of dispersal.

The primary regions and their subdivisions, recognized in the preceding pages, are enumerated in the subjoined schedule.

1.-Primary divisions, or "Realms".

1. An ARCTIC, or NORTH CIRCUMPOLAR.

II. A NORTH TEMPERATE, divided into two regions and eight provinces.

III. An AMERICAN TROPICAL, with three regions. (Provinces not characterized.)

IV. An INDO-AFRICAN, with two regions and five provinces.

V. A SOUTH AMERICAN TEMPERATE, with two provinces. VI. An AUSTRALIAN, with three regions and two provinces. VII. A LEMURIAN.

VIII. An ANTARCTIC or SOUTH CIRCUMPOLAR.

2.-Secondary divisions, or "Regions".

II. North Temperate Realm: 1, American; 2, Europæo-Asiatic. III. American Tropical Realm: 1, Antillean; 2, Central American; 3, Brazilian.

IV. Indo-African Realm: 1, African; 2, Indian.

VI. Australian Realm: 1, Australian (Australia, Tasmania, and New Guinea); 2, Polynesian; 3, New Zealand.

3.-Divisions of third rank, or "Provinces".

II, 1. American Region: a, Boreal*; b, Eastern; c, Middle; d, Western. II, 2. Europæo-Asiatic Region: a, European; b, Siberian; c, Mediterranean; d, Manchurian.

IV, 1. African Region: a, Eastern; b, Western; c, Southern.

IV, 2. Indian Region: a, Continental; b, Insular.

V.

South American Temperate Realm: a, Andean; b, Pampean. VI, 1. Australian Region: a, Australian; b, Papuan.

* A "Boreal" province has not been distinctly recognized in the preceding pages as a division belonging to the same category as the other so-called or commonly recognized provinces, and is not at all recognized in the table of distribution given at p. 339. It is nearly equivalent to what is there implied by "Cold Temperate". I hope soon to be able, in a paper to be devoted especially to a consideration of the geographical distribution of North American mammals, to define and characterize it more definitely.

The relation of the different primary regions and their subdivions may be approximately indicated diagrammatically as follows:

ART. XVI.-DESCRIPTIONS OF NEW EXTINCT VERTEBRATA FROM THE UPPER TERTIARY AND DAKOTA FORMATIONS.

By E. D. COPE.

CARIACUS DOLICHOPSIS, sp. nov.

John Collett, of the Geological Survey of Indiana, discovered in a late lacustrine deposit in Vandenburg County, Indiana, a number of Postpliocene fossils. One of these is the ulno-radius, etc., of a Bos, and another is the left mandibular ramus of a deer, probably of the genus Cariacus. The jaw differs in its proportions from those of C. virginianus, C. macrotis, and C. columbianus, with a considerable number of which I have compared it. It belonged to an animal of the average size of the C. virginianus, but differs in having the diastema an inch or more longer, while the tooth-line is shorter. Placing the first molars in line, the last molar of the fossil form attains only the penultimate column of that of the C. virginianus; in some cases just a little farther. On the other hand, the angle of the mandible extends beyond that of the C. virginianus, and the slope of the anterior base of the coronoid process is more gradual. At the same time, this portion is less oblique in the transverse direction, owing to the prominence of the external face of the ramus. This ramus differs also in the great prominence and anterior position of the posterior edge of the masseteric fossa, which leaves behind it a wide oblique face little developed in the existing species. The species being clearly new, I call it Cariacus dolichopsis.

The intercolumnar tubercles are small, and are only present in the true molar teeth. The molars are about half-worn; at this stage, the anterior lake of the three last, communicate with the median inner vertical fissure, by their posterior horn.

AUCHENIA VITAKERIANA, sp. nov.

This llama is represented by a portion of the left maxillary bone supporting molar teeth, which was found in a Pliocene deposit in Oregon, in association with two larger species of the genus, the A. hesterna and the A. major (Palauchenia Owen). Its size is less than those attained by the two species named, but exceeds considerably that of A. lama of the Andes. The details of the structure of the first and second true molars are quite similar to those of the existing species. The last premolar is broken away, but its roots show that its size was considerable, lacking little in antero-posterior diameter that of the first molar. The base of the first (or third) premolar is very small. It possessed either but one small root, or possibly two, the second being represented by a small fossa on the inner side of the anterior root of the last premolar, of doubtful siguificance. The palatal foramen is opposite the line of contact of the two premolars, instead of anterior to the first, as in A. lama. The infraorbital foramen is over the line of contact of the last premolar and first true molars.

This species is dedicated to Governor John Whitaker, of Oregon, who discovered the locality from which this fossil was obtained. The formation is Pliocene.

TICHOLEPTUS ZYGOMATICUS, gen. et sp. nov.

Char. gen. This genus is known from cranial characters only. Dental formula, I.; C. † ; Pm. 4; M. 3. Teeth in general similar to those of Oreodon; the true molars with short crowns; the first inferior premolar the functional canine. Premaxillary bones consolidated into a single mass; symphysis not co-ossified. A preorbital fossa, and a large foramen in front of it, bounding the maxillary bone superiorly and posteriorly. No vacuities between the orbits.

This genus of Oreodontidae occupies an interesting position between the three prominent forms of the family, Oreodon, Merycochorus, and Leptauchenia. It combines the dentition and preorbital fossa of the first with the solid premaxillary of the second and the large facial vacuities of the third.

Char. specif.-The T. zygomaticus is only known from the cranium of