662 THE AMERICAN NATURALIST. | [Vor. XXXVI. 
Geographic distribution (of palustris, typicus): Southern New Jersey 
to northeastern South Carolina. 
Habitat: Tide marshes of the coast, inland to the limits of brackish 
water. Wintering in muskrat houses in New Jersey. 
Description of species : Size, smallest of the Atlantic coast group. Skull, 
relatively large and massive. Colors, above grayish black with pale tawny 
or ashy suffusion. Underparts wholly grayish white. Fur dense and soft. 
Average measurements of ten old adults from New Jersey and North 
Carolina: total length, 237 mm.; tail vertebre, 108 mm.; hind foot, 
29 mm.; ear from crown, 12 mm. Skulls of two old males, total length 
(basilar, of Hensel), 37 mm. ; zygomatic width, 18 mm. 
2. Bachman's marsh or rice mouse, Oryzomys palustris oryzivorus (Bach- 
man). 
1853 Arvicola oryzivora Bachman. Quad. N. Amer. Vol. iii. p. 214 
1893 Oryzomys palustris natator Chapman. Bull. Amer. Mus. Nat. 
ist. Vol. v, pp. 43-48. 
1894 Oryzomys palustris texensis Allen. Bull. Amer. Mus. Nat. Hist. 
Vol. vi, pp. 177-179. 
Type locality: Southeastern South Carolina, between Charleston and 
Savannah, Ga. 
Geographic distribution : Northeastern South Carolina to Orange and 
Citrus Counties, Florida, Gulf coast to southern Texas. 
Habitat : Same as palustris, but penetrating farther inland to fresh water. 
Description of species: Compared with palustris of New Jersey and 
northern North Carolina (Bertie County) the differences of Georgia and 
north Florida specimens, alike typical of oryzivorus and natator, are too 
slight to allow of the recognition of both the latter-named races. In fact, 
no palpable departure from palustris is manifest until north Florida speci- 
mens are examined. As the zafator form is thus synonymous from an 
anatomic and zoógeographic standpoint with Bachman’s type, I am forced 
to so consider it in this review. 
Oryzivorus, as thus restricted, may be distinguished from palustris by 
somewhat larger size, a relatively much lengthened tail, and a narrower 
skull. It is a more slender, elongate animal. The colors of upper parts 
are browner (less gray) than palustris, the subapical third of the hairs of 
back and sides being pale ochraceous brown instead of pale tawny. T9 
buffy shade invades the underparts and gives a slightly soiled wash thereto 
even on breast and belly, as contrasted with the uniform clear ashy white 
of palustris. Average measurements of three adults from St. Mary's, Ga-: 
total length, 255 mm.; tail vertebra, 118 mm.; hind foot, 30 mm. ; ear 
from crown, 15. mm. Of five males from Gainesville, Fla. (from type 
locality of zatator, fide Chapman): total length, 286 mm.; tail vertebra, 
136 mm. ; hind foot, 33 mm. ; 
. Tę will be seen by above figures that the difference in length consists 
chiefly in the great relative lengthening of the zail, the body being not 


