WEST COAST PULMONATA. 23 



spread most widely, the angled, or even the depressed shells, 

 being best suited to crawl into the deep fissures of the earth, 

 rocks, or under logs, must oftenest escape burning, and thus 

 become the prevailing forms stocking those regions. Thus 

 may be explained the distribution of such forms as A. (cal.) 

 ramentosa (No. 32), which prevails over most of the two 

 counties east of San Francisco Bay, while A. exarata takes 

 the place of A. arrosa in most of Santa Clara valley, but is 

 less common west of the Santa Cruz Mountains. 



An aj)proach to the angled form is sometimes seen in 31. 

 armigerus (No. 25), but as that species only lives in very 

 damp places, this variety may be of different origin. The 

 imperforate and toothed variety is given as Ancey's type, 

 but the umbilicated toothless form is the most common, 

 being very near that found in Plumas County. 



Mr. Badger has lately brought from Eel Eiver, Humboldt 

 County, near lat. 40°, and perhaps 1,000 feet elevation, the 

 largest specimens of C. ? in/nmafa I ever saw. One belongs 

 to Binney's smooth variety, but is nearly destitute of angle, 

 and though very dark has a darker line on the body whorl, 

 and traces of the impressed revolving grooves of Jidelis. It 

 measures in breadth 1.74 inch, axis 0.76, alt. 0.90, being of 

 about three times the bulk of Alameda County shells, and 

 with only traces of their peculiar epidermis, but is a dead 

 shell somewhat worn. It is the largest land-shell I have seen 

 from the west coast of the United States. 



A smaller, less worn shell, from the same place, is 

 more angled, but the surface even more like that of Jidelis, 

 shining beneath, but band very faint. They might in- 

 deed be almost called a black variety of Jidelis, and are 

 truly intermediate. The largest has about the width of the 

 great G. netuherrt/ana figured in Binney's 1st Suppl., PI. IV., 

 but is higher and heavier. With them are some of A. arrosa, 

 very large and approaching the form I called arhoretoriim 

 Val., also one 31. vancoaverensis nearer the Oregon shell than 



