1879.] NATURAL SCIENCES OF PHILADELPHIA. 187 



specimen, and in the other they are wanting. The III. and IV. in- 

 ferior premolars have marginal posterior lobes. The inferior sec- 

 torial, as already stated, has no inner tubercle. Its heel is peculiar 

 in the great elevation, and submedian position of one of its bor- 

 ders, approaching Temnocyon in this respect. The other edge is, 

 however, distinct, thus forming an unsymmetrical basin. The first 

 inferior tubercular is small, one-rooted, and the crown is subround, 

 and with a single median tubercle. In the other usual species of 

 Canis, Vulpes, and of many other genera of the family, this tooth 

 is elongate, two-rooted, and supports at least two tubercles. 



The general form of the crania resembles those of some of the 

 terriers. The brain-case is full and convex, the orbits are lateral, 

 and the muzzle is moderately elongate and narrowed. The osseous 

 surfaces are generally smooth, and there is no indication of the 

 ridge bounding the temporal fossa above. There is a deep sinus 

 of the superior border of the foramen magnum, a character above 

 noted as occurring in a subspecies included under Canis famili- 

 aris. 



I have been unable to ascertain whether the species now de- 

 scribed is one of the forms which have been referred to Canis 

 familiaris under a subspecific name. One of the specimens was 

 presented to the Academy many years ago by Dr. Paul Goddard, 

 under the name of lap-dog. The form of the head shows that it 

 is not one of the forms of Canis extrarius hispanicus (of Fitz- 

 inger's Work on Dogs), which are represented by the King Charles 

 Spaniel, and other lap-dogs. As I can find nothing concerning it 

 in the books I give it a provisional specific name. 



The origin of the characters of this genus is doubtless to be 

 traced to prehistoric time, if not to an early tertiary geologic age. 

 Perhaps some of the species' characters are of later origin ; such 

 as the obliteration of the superior border ridges of the temporal 

 fossae, and the large sinus of the foramen magnum. These cha- 

 racters, seen in a lesser degree in a domesticated true Canis, as 

 above mentioned, are evidently an adaptation to an enlarged brain ; 

 the one to the increased cerebral hemispheres, the other to the 

 protuberant vermis of the cerebellum. Whether these characters 

 are due to a prolonged domestication, and abnormal nutrition 

 within human habitations, remains to be ascertained. ' I remark 

 here that two crania of dogs found mummied in Egypt by Mr. 



