12 PROCEEDINGS OF THE ACADEMY OF [1890. 



ON THE DISTRIBUTION OF COLOR-MARKS IN THE PTEROPODID^. 

 BY HARRISON ALLEN. 



In a paper which I contributed to these Proceedings, 1888, p. 84, 1 

 endeavored to establish the proposition that the arrangement of the 

 fur and the markings upon the skin in the mammalia were capable 

 of being systematically treated. Especially I endeavored to corre- 

 late the location of color-marks with physiological or morphological 

 factors. Thus some of the markings are due, it is thought, to effects 

 of heat and moisture, others to the presence of important glands, or 

 of special organs ; a third group was explained ou the basis of bi-lat- 

 eral symmetry, etc. 



The essay now presented is confined to the further elucidation of 

 the subject, as illustrated in the fox-bats. Conformation to a gen- 

 eral type of coloration is here easily discerned. While writers have 

 mentioned some of the details, no evidence is presented why they may 

 not constitute the plan upon which descriptions of species should 

 be based. That some plan is needed is evident. In no group of 

 mammals is it more difficult to identify si^ecies where no assistance 

 is afforded by the examination of types or of collections which are 

 authoritatively named. I hope that this difficulty may be lessened 

 by mapping out the hair-bearing surfaces into regions, and by sep- 

 arately describing each. The study of variable species is one of the 

 most interesting phases of modern zoology ; the time has come ap- 

 parently to devote greater care than has been the custom to the 

 most variable of all the chai-acters of the mammalia, namely, the 

 quality, coloration, and distribution of the hair. This exj^lanatiou 

 is necessary to account for the minute description of well-known 

 forms of bats in the ensuing pages. 



The regions which will receive names in the descriptions are as 

 follows : 



The crown. 



The face. 



The " whisker." 



The inter-ramal space, i. e. — the region between the horizontal 

 rami of the mandible. 



The post-mental space, i. e. — the space directly back of the men- 

 tum. 



The occiput. 



