POSITION AND RELATIONSHIPS OF MUSTELID.E. 3 



the one hand and the Urslrlcc on the other. In order to give a 

 clear idea of the position and relationships of the Mustelldw, the 

 following characters* of the higher gronps of Mammals under 

 which the family comes are given : — 



Mammals having a brain with the cerebral hemispheres connected by a 

 more or less well-developed corpus callosum and a reduced 

 anterior commissure. Vagina a single tube, but sometimes 

 with a partial septum. Young retained within the womb till 

 of considerable size and nearly perfect development, and deriv- 

 ing its nourishment from the mother through the intervention 

 of a " placenta" (developed from the allautois) till birth. Scro- 

 tum never in front of penis. . . (Subclass) Moiiodelphia. 



Brain with a relatively large cerebrum, behind overlapping much or all 

 of the cerebellum, and in front much or all of the olfactory 

 lobes; corpus callosum (attypically) continued horizontally 

 backwards to or beyond the vertical of the hippocampal suture, 

 developing in front a well-defined recurved rostrum. 



(Super-order) EDUCABILIA. 



Posterior members and pelvis well developed (in antithesis with the 

 Cetaceans and Sirenians). Proximal segments of both fore 

 and hind limbs (upper arm and thigh) more or less enclosed in 

 the general integument of the trunk (in antithesis with the 

 order Primates). Clavicles rudimentary or wanting. Scaphoid 

 and lunar bones of the wrist consolidated into one (scapho- 

 lunar) carpal. Digits clawed (not hoofed). Teeth of three 

 kinds, all enamelled; incisors |5| (exceptionally fewer); ca- 

 nines specialized and robust; one or more molars in each jaw 

 usually sectorial. Brain without calcarine sulcus. Placenta 

 deciduate, zonary. (=The Carnivora or " beasts of prey" of 

 ordinary language.) . (Order) Fer.e. 



Body elevated and adapted for progression on land by approximately 

 equal development, freedom, and mobility of fore and hind 

 limbs. Tail free from common integument of body. Ears 

 well developed. Functional digits terminating in claws. 

 Digits of neither fore nor hind feet webbed to the ends (ex- 

 cepting the hind feet of Enliydra) ; inner digits of fore feet not 

 produced beyond the rest; inner digits of hind feet seldom 

 thus produced, but often reduced or atrophied. (All these ex- 

 pressions in antithesis to the Finnipedia, or suborder of the 

 Seals.) ■ (Suborder) FissiPEDiA. 



* For which I am principally indebted to Dr. Theo. Gill. (Smithsonian 

 Miscellaneous Collections, j — 230— | Arrangement | of the | Families of 

 Mammals. | With analytical tables. | Prepared for the Smithsonian Institu- 

 tion. I By Theodore Gill, M. D., Ph. D. | [Seal.] | Washington: | Published 

 by the Smithsonian Institution. | November, 1872. | [8vo. pp. i-vi, 1-98.]) 



