PHILOSOPHICAL SOCIETY OF WASHINGTON. 119 



or become known which compel the recognition of new subordinate 

 groups in the order; and Major Dobson has also proposed to raise 

 the Solenodontinse from the rank of a subfamily of Centetidre to 

 that of a family by the side of the latter. The assessment of the 

 comparative value of different groups is a difficult and delicate 

 task, and much can be said for as well as against any given propo- 

 sition. The Solenodonts are doubtless as distinct from their nearest 

 of kin as are some of the generally admitted families of mammals, 

 and therefore it will be quite proper to recognize the family value 

 of the type. But there are other groups of Insectivora which have 

 been associated together in the same families which are equally or 

 more entitled to the same distinction. Indeed, the only subfami- 

 lies of the "Synopsis of Insectivorous Mammals" which do not 

 contrast more seem to be the Gymnurinse and Erinaceina3. If the 

 Solenodontidae are to be differentiated with family rank from the 

 Centetidaa, so should the others. We would then have the follow- 

 ing families: 



SUBORDER DERMOPTERA. 



1. Galeopithecidse. 



SUBORDER BESTIiE. 



Dilambdodonta. — Bestise with broad molar teeth surmounted 

 by W-shaped ridges. 



TUPAIOIDEA. 



2. Tupaiidae. 



3. Macroscelididre = Macroscelidinse. 



4. Rhynchocyonidaa = Rhynchocyonince. 



ERINACEOIDEA. 



5. Erinaceidte, with the two subfamilies Gymnuriure and Erina- 

 ceinaa. 



SORICOIDEA. 



6. Talpidse = Talpinse. 



•7. Myogalidee = Myogalinae. 

 8. Soricidse. 



Zalambdodonta. — Bestise with narrow molar teeth having V- 

 shaped ridges. 



