HOWELL — NEW BEACH MOUSE FKOM FLORIDA 
237 
DESCRIPTION OF A NEW SPECIES OF BEACH MOUSE FROM 
FLORIDA 
By Arthur H. Howell 
The group of mice typified by the oldfield mouse (Peromyscus 
polionotus) is a plastic group, occupying a rather limited area in 
Georgia, Alabama, and Florida, but splitting into a number of well- 
marked forms. In the interior these mice live chiefly in sandy fields, 
either cultivated or uncultivated, and on the coast occupy the sandy 
ocean beaches where the vegetation consists chiefly of sea oats {Uniola 
sp.) and scattering clumps of bushes. 
In Florida, five forms are at present recognized, four on the main- 
land and one on Anastasia Island (opposite St. Augustine). Osgood^ 
gives all of them the rank of subspecies and (with the possible excep- 
tion of phasma) this seems to be the logical course, but too little col- 
lecting has been done to permit of defining exactly the ranges of the 
various races. In general, however, we know that typical polionotus 
occupies southern Georgia, the greater part of eastern Alabama, and 
extreme northern Florida; niveiventris is apparently confined to the 
ocean beaches on the Atlantic coast from Hillsboro Inlet north to 
Mosquito Inlet; rhoadsi occupies the western side of the peninsula in 
the region north of Tampa Bay and possibly ranges most of the way 
across to the Atlantic side, probably intergrading with both niveiventris 
and polionotus; albifrons is known from the region around Choctaw- 
hatchee Bay, extreme western Florida, and from the ocean beaches 
in southeastern Alabama east of Mobile Bay; phasma is confined to 
Anastasia Island. 
The discovery of a strikingly marked new species on Santa Rosa 
Island — a narrow sandy island about 50 miles long extending from the 
mouth of Pensacola Bay to the mouth of Choctawhatchee Bay — is 
rather surprising and of great interest. The island is separated from 
the mainland only by a shallow bay, in places not over a quarter of a 
mile wide but the species living on the island is totally unlike the form 
found on the nearby mainland. It is by far the palest form in the 
group and, unhke the races occupying the beaches of eastern Florida, is 
of a drab rather than a buffy tone. 
The form occupying the mainland opposite Santa Rosa Island — 
albifrons — ranges also, as has been stated, over the Gulf beaches of 
^ Osgood, W. H., N. Am. Fauna no. 28, pp. 104-109, 1909. 
