14 



erence to these sources of information is seldom made, since most of 

 the Hterature is so well known as to make this unnecessary. 



In the following list of species, frequent reference is made to the 

 common environments of sand-prairie animals, such as bunch-grass, 

 blowsand, blowout basin, etc. These environments are described with 

 the associations of the same names in the section dealing with the 

 associations of the sand prairie. 



GASTROPODA 



The acidity of the soil in the sand regions, its low content of cal- 

 cium carbonate, and other adverse conditions, exclude practically all 

 snail life from the sand prairie. No snails at all were seen during the 

 summer, and in the spring only three empty and worn shells were 

 found. Two of these were aquatic species, and the third was an in- 

 habitant of deep forest, all being utterly foreign to sand prairie. The 

 species were as follows: Planorhis trivokis Say, from a sandy lane 

 at the Devil's Hole; Caiiipdonia intcgrinii De Kay, from a sandy 

 roadside east of Havana; and Pyramidula soUtaris Say, from a blow- 

 out at the Devil's Neck. (Determined by J. Zetek.) 



Order ougochakta 



Diplocardia sp. (indeterminable). April 4. 



One specimen taken under a board with Lithohius and Lacon rect- 

 angularis, in bunch-grass; and another, probably of the same species, 

 found in a similar situation on another dune. Earthworms, besides 

 eating small living organisms, feed on the organic part of the soil; 

 and as sand has a very small humus content, earthworms are very rare 

 in it. The humus present may be due largely to the decay of boards 

 or logs. 



Order chii^opoda 



LitJiobius s,\). (indeterminable). April 4, 5. 



One specimen taken under a large board near a dune summit. The 

 soil had quite a little humus, indicating rather an advanced stage of 

 bunch-grass. Another, taken from under a log at the edge of a field. 

 Centipedes are very rare in the sand prairie, the soil conditions being 

 unfaxorable. The genus is predaceous. 



Order diplopoda 



Parajidus sp. (indeterminable). April 6. 



Several specimens in a non-typical part of the Devil's Hole bunch- 

 grass. Considerable humus was in the soil. The scarcity of organic 



