148 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.40. 



several very small and delicate humus-inhabiting creatures, such as 

 ScolopendreUa, Pauropus, Japyx, and Campodea. The finding of a 

 relatively large tropical milliped (Eurelus, new genus, order Anocheta) 

 in the same locality, may be taken to indicate that permanent moisture 

 has not been confined to the lower layers of the soil, but has existed prac- 

 tically on the surface. Though these larger millipeds are undoubtedly 

 able to endure much more exposure to dry air than the smaller and 

 more delicate types mentioned above, they can hardly be expected 

 to survive any such complete exposure as would follow the destruction 

 of all the forest growth. The more minute animals are able to crawl 

 into small cracks and interstices, and thus take advantage of any 

 moisture that exists, even at considerable depths. The evidence of 

 continuous humidity is strengthened by the finding of relatively large 

 species of millipeds that remain nearer to the surface. 



These facts indicate that some of the present forest growth in the 

 vicinity of Falfurrias is not of recent origin, but may represent a rem- 

 nant of earlier and more continuous forests. There is a rather densely 

 wooded area to the northeast of Falfurrias, consisting of a slight 

 depression where the water collects after rains and stands in small 

 pools long enough apparently to prevent the growth of grasses, and 

 thus to give protection against the prairie fires that might otherwise 

 have destroyed the woody growth and obliterated the last traces of 

 the millipeds and other humus-inhabiting types of animal life. 



The existence of any form of arthropod life in the soils of south 

 Texas is in striking contrast with the black-land prairies farther 

 north, those that form the so-called "hog wallows." The soil of the 

 black-land prairies is remarkably devoid of life of any sort; even the 

 agricultural ants are unable to occupy the typical black-land prairie. 

 The soil cracks during drought to the depth of several feet, and 

 then dissolves into a very adhesive, pasty mud when the rain comes. 

 Delicate animals would find no protection in drought, and the more 

 hardy would be drowned or smothered in their burrows in times of 

 floods. One group of large heavily armored millipeds of the order 

 Diplocheta is able to live in deserts of west Texas and Arizona by 

 virtue of their habit of burrowing, taking advantage also of the deep 

 excavations of the burrowing rodents that are so abundant in the 

 deserts. 



The preservation of even a remnant of permanent forest in such a 

 place as Falfurrias under present climatic conditions might not 

 strike the observer as being at all probable, were it not for the con- 

 crete evidence afforded by the existence of these animals. Local 

 opinion declares that this district has become distinctly drier in the 

 last twenty years. Surface wells and pools that were formerly relied 

 upon to furnish permanent supplies of water for stock have completely 

 dried out, in the last decade, over a considerable section. This has 



