81 Proceedings of the Biological Society of Washington. 



breadth, 13.2; mastoid breadth, 11.4; least interorbital breadth, 4.2; 

 alveolar length of upper molar row, 5.1. 



Remarks. — Considering the nearness geographically of this species to 

 Pitymys pinetorum of South Carolina and Georgia, the differences between 

 them are remarkable. Further collecting in northern Florida may show 

 that they intergrade, but for the present it seems best to regard parvulus 

 as a distinct species. 



The habits of this species are described by Mr. Jackson, as follows: 



' ' This little mouse usually selects areas that are covered with a dense 

 growth of trees and shrubs, mainly sand pine and scrub oak. No runways 

 were found in the openings where there were no trees. They dig burrows 

 ranging from about three-fourths of an inch to an inch in diameter and 

 running from one to five or six inches below the surface. These runways 

 weave in and out around the roots of the trees and shrubs ( on which no 

 doubt the mice feed to a great extent) and do not run in a straight line 

 for any distance, probably not over a foot or two. The little animals 

 also use the mole runways, probably after they have been abandoned by 

 the mole. (One adult specimen was caught in a mole runway. ) Several 

 attempts to follow runways to the nest of the mouse finally resulted in 

 finding a nest under an old board. It was made of palmetto bark and 

 lined with a silky, fibrous material, much like the inside of a milk-weed 

 pod. Around the nest was found the hulls of about two hundred pine 

 seeds." 



