586 General Notes. {July, 
varieties belonging to the fresh-water fauna are less numerous, 
though they occur in perhaps greater relative abundance, Limnea 
being the genus most numerously represented. The kinds found 
were /Yelicina oculata Say, Pomatiopsis lapidaria Say, Limnea hu- 
milts Say, L. reflexa Say, L. caperata Say, Physa heterostropha Say, 
Planorbis trivolvis Say, Segmentina armigera Say, Valvata tricart- 
nata Say, Spherium striatinum Lam., and an occasional fragmen 
ot Anodonta (?). The last has-never been found in a sufficiently 
well preserved condition to make a sure generic classification. 
No remains of Unio have ever come under my notice. € 
nature of the sediment composing the loess, together with the 
habits of the genera above indicated, all of which inhabit com- 
paratively still and shallow waters, will enable us to gain a fairly 
correct idea of the conditions under which the deposit was 
formed. These lists ah do i they can to determine the 
origin of the loess, which, so far as their individual testimony goes, 
was lacustral.—R. Ev/sworth Call, Des Moines, lowa. 
Tue RopentiA oF THE AMERICAN Mrocene.—The following 
catalogue shows the affinities of the members of the order Roden- 
tia found hitherto in the White river, Truckee and Loup Fork 
horizons of the Miocene: 
i Picante tot Squirrels. 
Sciurus vortmani re Pal. Bull. 31, p. 1 oe Tru ‘vel 
Sciurus relictus Cope (Pa ete New Vertebr. Cotarado, 175, p. 3. White river. 
Sciurus ballovianus Cope ; Bullet, U. S, Geol. Surv. Ter , 4581. 2 uckee 
Gymnoptychus minutus a Pal. Bull. No. 16, p. 6, “oak “White river. 
Gymnopiychus trilophus Cope; Pal. Bull., No. 16, p. 6, 1873. White river. 
Meniscomys hippodus Cope; Pa 1. Bull., No. 30, p. 5, 1878. Truckee. 
Rbncauays liolophus Cope; Rept. U. : Geol. Surv. Terrs., tv, MS. Truckee. 
Meniscomys cavatus Cope; ‘Rept. U. S. Geol. Surv. Terrs., 1v, MS. Truckee. 
Meniscomys nitens Marsh; Am. Journ, Sci. Arts, ie 1877. Truckee. 
Ts 
Ischyronys typus Leidy; Ext. Fauna 0% Nebr 1869, 335- _. White river. 
Cast 
tor peninsulatus Cope, Report U. S. ove a spin rv. — 1v, MS. Truckee. 
care gradatus Cope Ccnsies. Pal. Bull., 30, p. 1878. Truckee. 38. 
— Cast lic sabanaiancs Leidy (Stencofiber) ; Ext. ‘Mamm. Da. Nebr., ee Eo 
Castor pansus Cope; Report U.S. Expl. Surv. W. of 100 Mer., IV, P- soe 1077 
Eucastor tortus Leidy; Ext. Mamm. Dak., sal ., 1869, p. 341. Loup Fork. 
MYLAGA as 
Baines wees sesquipedalis Cope; Bull. U. 'y an Surv. Terrs. 1873, P- 384- ye 
Slytelpinahes: monodon Cope; Rept. U. S. vere Surv., Iv, MS. Loup Fork. 
?F 
Heliscomys velus Cope; Synopsis New thee Eileradé 1873, p- 3 White river. 
MYOMORPHA. Mice, etc. 
Mur mph 
Padiys elegans Leidy; Ext. Mamm. Dak., , 1869, p. 342. White river. 
Hesperomys nematodon Cope; Pal. Bull., a 31, p Is £870) Truckee. 
— 
