1894.] NATURAL SCIENCES OF PHILADELPHIA. 181 



June 5. 



Mr. Charles Morris in the chair. 

 Twenty-three persons present. 



June 12. 



Rev. Henry C. McCook, D. D., Vice-President, in the chair. 



Thirty-one persons present. 



Tlie following were presented for publication : — 



Certain Sand Mounds of the St. Johns River, Florida. Part II. 

 By Clarence B. Moore. 



Crania from the Mounds of the St. Johns River, Florida. By 

 Harrison Allen, M. D. 



On a New Species of the Isopod Genus Bathynomua. By Dr. A. 

 Ortmann. 



The Changes which Take Place in the Skull, Coincident with Short- 

 ening of the Face-Axis. — Dr. Harrison Allen remarked that the 

 anatomist, while interested in establishing co-ordinates, is well aware 

 of the difficulties which are continually encountered. Still it must 

 be acknowledged that co-ordinations exist between the component 

 parts of every organism and as knowledge extends they will be 

 gradually formulated. 



The ensuing observations may be of value in denoting the kinds 

 of changes which take place in the skull upon the shortening of the 

 face- axis. 



It has been assumed by authors that the shapes and positions of 

 the teeth are the chief agents in modifying the shape and the size 

 of the region of the face. In Chiroptera this is not the case. In 

 comparing the cranium of the long-faced Choeronycteris and the 

 short-faced Ametrida, it is remarked that not only are the face- 

 proportions contrasted, but those of the zygomatic arches are changed 

 (namely, in being slender or absent in the one and high in the 

 other), while the face is broad at its base and the mesopterygoid 

 fossa widened. The greyhound and the English pug-dog exhibit 

 similar contrasts. In these varieties, in addition, the tympanic bulla 

 is relatively larger in the pug-dog than in the greyhound. In Pro- 

 boscidea the contrast between the length of the face-axis in Mastodon 

 and Elephas can be expressed in the development of the pneumatic 

 spaces in the skull ; not, indeed, l)y the inflation of the tympanic 



