142 BE. WALTER. KIDD ON PROPOSED ADDITIONS [Jan. 19, 



2. On proposed Additions to the accepted Systematic 

 Characters of certain Mammals. By Dr. Walter 

 KiDD, F.Z.S. 



[Received October 9, 1903.] 



(Text-figure 3.) 



There are certain modifications of the arrangement of hair in 

 many groups of Mammals which seem to be of suificient import- 

 ance and constancy in regard to taxonomy to justify attention. 

 Those which are here brought forward are the most prominent of 

 theii- kind, but doubtless many others will also yield results under 

 further examination. No attempt is made to interfere with 

 accepted classification or to point out new affinities. Such 

 observations as there are tend to support rather than to challenge 

 the established views. 



It is a fact that many diflferent species have an arrangement 

 of their hairy coverings which is quite characteristic, and cei-tain 

 genera, families, and orders also have their own plan, and within 

 these groups individuals may vaiy slightly from the normal type 

 of the group. 



Two classes of phenomena are here chosen for a preliminary 

 study. First, the arrangement of hair on the head and face, 

 chiefly the naso-f rontal region. Second, the distribution of whorls, 

 feathering, and ci-ests on the neck, trunk, and limbs. 



I. The Arrangement of Hair on the Head and Face. 



In the fii'st place, there are two types of the arrangement of 

 hair on the naso-frontal region. The hair may take that which 

 seems to be the primitive course and pass from the premaxillaiy 

 region, with slight modifications for difierent forms of skull, 

 towards the frontal and parietal regions. This is well illustrated 

 on the heads of Cervidfe and Canidfe, is far the more common 

 arrangement, and is found in the lai'gest groups. In many 

 instances, as in Canidaj, there is found at the distal edge of the 

 hairy portion of the muzzle a whorl, from which the stream of 

 hair may be considered to take origin. In others, as in Cervidte, 

 the non-hairy portion of the mu,zzle is broader and extends 

 further along the premaxillary region and no whorl is found. 

 A totally dififerent arrangement of the naso-frontal hair-streams 

 is found in a smaller number of animal forms, all belonging to the 

 Ungulate ordei-, its best development being seen in the Domestic 

 Horse. Hei'e the starting-point of the stream is a whoid in the 

 frontal area situated at, or just above, or below, the level of the 

 orbits, from which two streams proceed, the larger and proximal 

 one to the ears and neck, the smaller and distal one to the pre- 

 maxillary region, diverging on eaeh side of the face. The whorl 

 on the frontal area thus divides the naso-frontal stream. 



Under this type may be classed the arrangements of hair of 



