NO. nil. . PROCEEDINGS OF THE NATIONAL MUSEUM. 335 



of the boundary line wliicli divides the two; (2) the Texan region, to 

 the east of the llio Grande and south to the Gulf of Mexico; the fauna 

 of this region is hardly to be discriminated from that of the State of 

 Tamaulipas, west of the river, but in which no collections were made 

 by the Commission; (3) lastly, west of the Colorado Eiver in Southern 

 California, the Californian coast fauua is encountered, and collections 

 were made, not only on the mainland, but also on San Clemente Island, 

 some 60 miles off" the coast. 



THE SPECIES OF THE CENTRAL OR SONORAN REGION. 



The following species were received from Dr. Edgar A. Mearns, 

 U. S. Army, from localities on either side of the international boundary 

 line between the Rio Grande Eiver, near El Paso, Texas, and the 

 Colorado Kiver of the West, near Yuma, Arizona. 



The plains are almost uniformly arid and fre<]uently alkaline, form- 

 ing what was formerly called desert, and quite unfit for the subsistence 

 of land snails. It will be understood that nearly all of the Tulmonates 

 were collected from the upper levels of the various mountain ranges 

 near the boundary, which rise from the plains into a region of moister 

 air, which, though still dry, supports a certain amount of vegetation. 

 Most of the snails are found dead on the surface of the soil; only when 

 infrequent rains occur do the live animals venture from the nooks and 

 crannies where they usually j^stivate out of reach of the collector. 

 Consequently good opportunities for collecting are rare and fresh 

 si)ecimeDS in a small minority. Even when fresh, many of them have 

 the well-known texture characteristic of dwellers in arid regions, such 

 as Arabia and the Sahara. 



LANB SHELLS. 



Family EN^DODOXTID^. 



Genus PYRAMIDULA, Fitzinger. 



Subgenus PATULA, Held. 



PATULA STRIGOSA, Gould. 



Typical specimens of this species were obtained at San Jose Moun- 

 tain, Sonora, Mexico; from Hachita (irande Mountain, Grant County, 

 New Mexico, and from the summits of the Huachuca Mountains, Ari- 

 zona, by Dr. Mearns and Mr, Holzner. A sharply carinated variety 

 was collected at Tanners Canyon, Huachuca Mountains, Arizona, by 

 Dr. Mearns. 



The normal form, very variable in coloration, has a somewhat dome- 

 shaped but low spire, appressed suture, and 5 whorls. It measures 11) 

 in minor, 25 in major diameter, with a height of 13 mm. The carinate 

 variety has a sharp peripheral keel, but is otherwise similar. 



