148 PROCEEDINGS OF THE ACADEMY OF [March, 



This form, which for the present we subordinate to the old S. laby- 

 rinthica, is the only Strohilops except S. hubbardi which I have seen 

 from Texas. It may be distinguished from *S. virgo by the costulate 

 base, wider umbilicus and far weaker inner parietal lamella. S. 

 strebeli is a much more depressed cone. 



The statement by Woodward,^" copied into American works, that 

 H. labyrinthica occurs in pretertiary Eiuropean strata, is misleading, 

 since the American species is really not identical with any from Euro- 

 pean strata, though there are numerous allied forms in the European 

 tertiaries. The genus became extinct in Europe, but survives in China, 

 Helix diodontina Heude being a Strobilops. In America it has not been 

 found in the Northwest or Pacific States, but extends south to Mexico, 

 the West Indies and Venezuela, and a species apparently belonging to 

 the genus has been described from the Galapagos. 



VALLONIID^. 

 Vallonia excentrioa Sterki. 



Galveston, under boards in a vacant lot. (Pilsbry, December, 1885.) 

 Vallonia perspeotiva Sterki. 



Texas : Drift debris of Devil's river, and of Pecos river near the High 

 Bridge, Val Verde county. Arizona: Benson, in drift of San Pedro 

 river. 

 Vallonia gracilicosta Reinh. 



New Mexico: Drift of Pecos river, at Pecos (Cockerell!). 

 Vallonia cyclophorella Anc. 



Arizona : Drift of San Pedro river, Benson, Cochise county, a single 

 specimen. 



COOHLIOOPIDiE. 



Shell oblong, cylindric-oblong or narrowly tapering, smooth and 

 glossy, with imperforate axis ; aperture ovate or acuminate, the columella 

 notched below or continuous with the basal lip. Foot without pedal 

 grooves. Kidney with direct ureter, of the Basommatophorous type. 

 Genitalia with a long appendix on the penis, as in Achatinella and the 

 Pupillidoe. Jaw and radula about as in Pupillidoe. 



This group has usually been included in the Achatinidoe or Stenogy- 

 ridoe, but the direct ureter removes it to a group of primitive snails 

 represented only by minute species in America, but by the beautiful 

 Achatinellidce and Partulidoe in Polynesia. Coecilianella (Cecilioides) 



I" Manual of the Mollusca, p. 286, edit. 2, 1868. 



