rs he, 
THE NATURAL HISTORY SURVEY. 315 
This species is very variable in this region, some forms 
approaching ampullacea Gould, while others might be taken for 
gabbt Tryon or virginea Gould, so far as form goes. It is prob- 
able that some west coast names will be added to the above 
synonymy, when more study has been given to this genus. 
This species is a triannuan. 
127a. Physa gyrina var. elliptica Lea, pl. xxxiv, fig. 5. 
Physa elliptica LEA, Trans. Amer. Phil. Soc., Vol. V, p. 115, pl. xix, fig. 
83, 1837. 
Physa aurea LEA, |. c., Vol. VI, p. 18, pl. xxiii, fig. 106, 1839. 
Physa troostiana LEA, Proc. Amer. Phil. Soc., Vol. II, p. 32, 1841. 
Physa nicklinit LEA, Proc. Phil. Acad. Sci., p. 114, 1864, 
Physa altonensis LEA, |. c., p. 114, 1864. 
Physa febigeriz LEA, |. c., p. 114, 1864. 
Physa oleacea TRYON, Amer. Journ. Conch., Vol. II, p. 6, pl. ii, fig. 6, 1866. 
Physa elliptica minor CRANDALL, The Nautilus, Voi. XV, p. 55, 1901. 
Shell; Differing from typical gyvina in being more ellip- 
tical, having a shorter, more rounded spire, and hence more 
convex whorls, the spire, as described by Tryon, ‘‘with the out- 
line not elevated above a continuation of the general curve 
of the body.” The shell is also more solid and the outer lip 
thicker, with a very heavy, bluish-white callus. The surface 
sculpture is the same as in gyvina. 
Length, 15.00; width, 7.50; aperture length, 9.50; width, 3.50 mill. —_ (8504.) 
5 TY OOS), &/$25) 6.005 %5 ¥s TADS teh s  BooO S (8504.) 
- E200. 2 Tabs a % A CR ais 1 Sea (8502.) 
Animal, Jaw, and Radula: As in gyrina. 
Distribution: Evidently the same as gyrina. 
Geological distribution: Pleistocene; Loess. 
Habitat: Almost always associated with gyrina. 
Remarks: he typical form of this variety seems at first 
quite distinct from gyrvima, but in a multitude of forms (the 
writer has examined several thousand specimens) is seen to 
fade imperceptibly into gyrima. From observations in the 
present area, gyvina would seem to be dimorphic, consisting of 
the typical gyrina with long spire and the,variety ed/iptica, with 
short, dome-like spire. This belief is strengthened by the fact 
that the two forms are always associated together. It is not 
quite as common as the typical form. 
128. Physa integra Haldeman, pl. xxxiv, fig. 6. 
Physa integra HALDEMAN, Mon., p. 33, pl. iv, figs. 7, 8, 1841. 
Shell: Oval, whorls four and one-half to five; spire short, 
