96 PROCEEDINGS OF THE ACADEMY OF [1888. 



In Lemur catta^ the prevalent color being squirrel gray, the white- 

 color between the eyes unites with the color round the eyes and 

 thence passes to the front of the neck. In another individual of the 

 same species (No. 268) the crown remains black, while the rest of 

 the collar is white. In Phoca fasciata a white band encircles the 

 head and neck at the region of the auricle. 



It will be seen from these examples that the color of the vertex 

 which may be defined as the crown of the head, excepting the mar- 

 gin near the occiput, is often white ; that this color tends to pass 

 down over the region of the ear to the neck, where it may unite 

 with the white of the ventre and embrace more or less of the arm. 

 With the exception of Phoca fasciata I have not met with this color 

 mark outside of the Quadrumana. Within the group last named 

 the band appears to be homologous with the hair of the crown and 

 the whiskers of the human subject. In the Saki the color is black 

 in this region and inclines forward to the submandibular growth 

 or the beard proper. 



The abruptness of termination of the white patch on the crown as 

 it approaches the occiput, appears to relate to the limitation of 

 baldness of the human subject, and explains the common retention 

 of hair at the line of the occiput. The occiput is under the control 

 of the causes which maintain the body color as distinct fi*om that of 

 the rest of the head. 



The Regions of the Special Senses — In addition to the dorsi-facial 

 stripe in the carnivores and the "collar," the mammalian head dis- 

 plays a very noteworthy feature in the retention of a contrasting- 

 color to the prevalent one of the body, about the nostrils, the eye- 

 lids and the auricles. Such a style of coloration is typically rep- 

 resented in Ailuropus melanoleucus, in which form the body color is 

 a dull white. According to Darwin^ the Himalayan rabbit at birth is 

 white, but in the course of a few months it gradually assumes dark 

 eyes, nose, feet and tail. The circumpalpebral black is found in many 

 animals Avhen the ear is imi^erfectly pigmented, as in Didelphys and 

 Solenodon. In Nycticehus javanicus the circle is brown. In Nycti- 

 pitheciis and Loris the two circumpalpebral circles unite in a median 

 dorsal line. In Nasua the circle is white. In Cercopithecus aethiops,. 

 C. collaris and C. fuliginosus the eye-lids are white. In many dogs 

 which are otherwise black or black and tan — a conspicuous black 



„ • 



1 Am. Mus. Nat. Hist. 270. 



2 Animals under Domestication I, 109. 



