162 THE CHICAGO ACADEMY OF SCIENCES. 
Type: Smithsonian Institution, one broken specimen (No. 5541) ; 
two specimens (Binney’s two original specimens) No. 8571. 
ANIMAL, JAW, RADULA AND GENITALIA: Unknown. 
RANGE: Idaho to Washington, north to central California. Pacific 
coast drainage of the Columbian and Californian regions, and the 
Transition and Upper Austral Life zones. 
RECORDS. 
UNITED STATES. 
CALIFORNIA: Antioch, Contra Costa Co. (Cooper). 
IpaAnHo: Near Challis, Custer Co. (Dall; Merriam; Stearns). 
WASHINGTON: Lake Vancouver, Clarke Co. (Gould; Wilkes). 
GEOLOGICAL DistripuTION: Unknown. 
Ecotocy: Not recorded. 
Remarks: Lepida appears to be a rare species, and has not been 
seen by the writer in any collection excepting that of the Smithsonian 
Institution, where Gould’s original specimens are deposited. As sug- 
gested by Cooper (Pr. Cal. Acad., IV, p. 51), it is very like a diminu- 
tive stagnalis and the figures published are strongly suggestive of the 
immature state of that species. The record from Meech’s Lake, On- 
tario (Trans. Ott. Nat. Field Club, I. p. 58), though said to have been 
verified by Tryon, is erroneous, the specimens being young stagnalis. 
A good series of this species from the original locality might prove 
it to be the young or a diminutive variety of stagnalis. Additional 
information is greatly needed. Gould’s observation concerning its re- 
semblance to pallida and desidiosa (obrussa) is not borne out by an 
examination of his type specimens. 
Genus PSEU DOSUCCINEA Baker, 1908. 
Pseudosuccinea BAKER, Science, n. s., XXVII, p. 943, June, 1908. 
Radix of authors. 
Type: Lymnea columella Say. 
SHELL: Of medium size, succineiform; spire generally short and 
somewhat dome-shaped ; last whorl very large, expanded; axis gyrate 
and imperforate; columellar plait not well marked; outer lip sharp. 
(Plate XVIII, fig. 5.) 
Jaw: Wide and low, with a bluntly rounded median projection. 
(elate VE hes.) 
RApuLA: With tricuspid lateral teeth; marginals serrated. 
GENITALIA: Prostate very small, cylindrical, with rounded ter- 
mination ; penis-sac retractors two in number; penis retractors inserted 
in posterior penis-sac retractor; penis short and thick, less than one- 
half the length of the penis-sac; penis nerve inserted in head of penis. 
(Plate X, fig. B:) 
