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NATURALIST'S GUIDE TO THE AMERICAS 



number and in proportions, and one finds 

 a good carpet of grass with xerophytic 

 annuals replacing the scrub under- 

 growth. 



This region marks the western limit 

 in Texas of the Virginia deer, but the 

 species is not abundant in the savanna. 

 The prairie spotted skunk (Spilogale 

 interrupted) comes into Texas from the 

 savanna to the north and it is found 

 pushing its way westward into the grass- 

 lands where local conditions of country 

 and vegetation permit. Here also ends 

 the range of several cottontail rabbits, 

 the raccoon (following up local aspects 

 of the heavier forest regions) and the 

 squirrels, previously mentioned, of the 

 Atlantic woodlands. One animal can 

 be cited as characteristic of that part 

 of the oak grove savanna which we 

 have mentioned as being cut off by the 

 deciduous forest. In that portion of the 

 savanna lying along the coast we find 

 the gulf spotted skunk (Spilogale india- 

 nola) whose range is entirely within 

 the savanna, being cut off and isolated 

 here by the heavy timber to the north 

 and the mesquite semi-desert to the 

 south. 



4. Coastal Prairie 



This is a relatively narrow band of 

 territory projecting southward along the 

 coast of Texas, wedging itself in between 

 the coniferous forest and the Gulf of 

 Mexico. Geologically, it is new land. 

 It is the westward extension of the region 

 of the Mississippi delta, and reaches 

 southwestward into Texas approxi- 

 mately to Matagorda Bay and the mouth 

 of the San Antonio River. It is a region 

 of little drainage and considerable rain- 

 fall (from 35 to 50 in.) and is so low that a 

 considerable part of it is practically a 

 brackish water meadow. Along the 

 coastline itself this merges into marsh 

 conditions, which are scattered all along 

 the gulf. The region is practically tree- 

 less except for a narrow strip of transi- 

 tion between the prairies and the forest 

 to the north and west, and is character- 

 ized by the presence of a rich, grassy 



vegetation composed of moisture-loving 

 species. This is particularly true over 

 the eastern two-thirds of the area, where 

 the rainfall is in excess of 40 in., while 

 the western third is marked by the 

 dominance of species demanding less 

 moisture as the area pushes southward 

 toward the semi-desert country. The 

 dominant species are the water grasses, 

 broom sedges (Andropogon spp.) panic 

 grasses and emersed aquatic plants. 

 Marsh grass (Spartinasp.) is abundant, 

 as is, locally, the dropseed (Sporobolus 

 sp.). 



It is not surprising to find within this 

 isolated and cut off region a number of 

 species of animals whose range does not 

 extend beyond the very limited confines 

 of this highly differentiated area. The 

 Florida opossum (Didelphis virginiana 

 pigra) is typical of the region, and is 

 closely confined to it. It is unknown 

 south of Matagorda Bay, and its range 

 extends north and east following the 

 coastal prairies along the coast. The 

 small mouse (Peromyscus taylon subater] 

 a very dark race, is confined to the dry 

 coastal prairies north of Matagorda 

 Bay, and is unknown from any other 

 region. Here it lives under the rich 

 carpet of grasses in the open country, 

 with habits that remind one of those of 

 a meadow vole (Microtus}. Associated 

 with it is the Louisiana vole (Microtus 

 ludovicianus] , also confined to the dry 

 prairies. The rice rat (Oryzomys palus- 

 tris texensis] is confined to the marshes 

 of the coast region, and is very common 

 throughout the wet areas, as is the 

 swamp woodrat (Neotoma floridana 

 rubida] whose range, however, has an 

 extension northward into the "big 

 thicket" of Hardin County. Closely 

 confined to these marshes one finds also 

 the coast swamp rabbit (Sylvilagus 

 aquations littlralis} which extend out 

 only to enter the big thicket where local 

 conditions are similar to those of the 

 coastal marshes. The typical swamp 

 rabbit (S. a. aquaticus} inhabit the 

 bottomlands of all streams of eastern 

 Texas. 



