OF NORTH AMERICA. 105 



overhanging flange internally, and flaring from posterior extremity as 

 far around as umbilical region; a minute umbilical chink is visible in 

 most specimens. 



"Dimensions : Altitude, 6 mm. ; latitude, 3 mm. ; altitude of body 

 whorl, 4.9 mm. ; longitude of aperture, 3 mm. ; latitude of aperture, 

 1.5 mm. (Arnold.) 



TYPE: U. S. Nat. Mus. no. 165426; cotypes, two specimens, Chi- 

 cago Academy of Sciences, no. 24678. 



HORIZON : Fernando formation, Pliocene Period ; fresh-water 

 portion at top. 



LOCALITY: One mile southeast of bench-mark 425, Los Alamos 

 Valley, Santa Barbara County, California. 



REMARKS: "This unique little fossil occurs in a peculiar fine- 

 grained gray clay in the upper portion of the Fernando formation, 

 where, at the type locality, near Los Alamos, it is quite abundant. 

 No other fresh-water species were found associated with it." (Arnold.) 



This is a peculiar little species recalling some forms of the recent 

 Galba caperata (Say). It also resembles immature individuals of Galba 

 catasc opium (Say), especially certain specimens from Ottawa, Ontario, 

 Canada. The species is, however, quite unlike any west coast Lymnaeid 

 living at the present time. It may possibly be an immature stage of 

 a much larger species. It is placed tentatively in Stagnicola. Addi- 

 tional material will probably settle the question of its affinities. 



PLEISTOCENE LYMN^AS. 



Galba bonnevillensis (Call). Plate XVII, figures 6-8. 



Limnaa catascopiumf HAYDEN, Prel. Rep. U. S. Geol. Surv. Wyoming, 

 p. 170, 1871. 



Limnophysa bonnevillensis CALL, Bull. U. S. Geol. Surv., no. 11, pp. 18, 

 24, 28, 48, pi. 6, figs. 10-13, 1884; Proc. Daven. Acad. Sci., V, p. 6, pi. 1, figs. 

 10-13, 1886. GILBERT, Mon., U. S. Geol. Surv., I, pp. 210, 298, 1890. 



Limncea bonnevillensis STEARNS, Proc. Nat. Mus., XXIV, p. 291, 1901. 



"SHELL umbilicated, elongate, ventricose or bullate, somewhat 

 solid, faintly striate and very minutely reticulated, below the suture 

 the last whorl bearing faint longitudinal ridges or costse ; spire elevated, 

 acute; suture deeply impressed; whorls 4 to 4^, very much rounded, 

 sometimes tending to geniculation above, the last whorl equal to three- 

 fourths the whole length of the shell, rapidly increasing in size, much 

 swollen, somewhat expanded at base; columella somewhat plicate, 

 slightly callous, regularly arcuate ; columella and peristome continuous ; 

 peristome simple, margins joined by a heavy callous which is con- 



