178 PROCEEDINGS OF THE JVTALACOLOGICAL SOCIETY. 



Connecticut River, south to Florida, west to Michigan, Arkansas, 

 und Texas, American Province. 



Quaternary : Loess of eastern States. 



lleported from Upper Columbia Lal<e, British Columbia, bv 

 ^\ hiteaves. The record is a dubious one. 



Ambloxus plicieerus (Lea). 



Melania plicifcra. Lea, 1838; 31. occafa, Hinds, 1844; 3L btdbosa, 

 Grould, 1847 (nornud) ; M. siUcula, Gould, 1847; M. ShaMensts, 

 Lea, 1856; M, nigrina. Lea, 1856 (normal); M. fVahlamatensis^ 

 'Lea,' Carpenter, 1857 (nude name); M. ^plicata, Lea ', Carpenter, 

 1857 (error ior plicifera); M. ' Shortensis, Lea', W.Cooper, 1860 

 (error for Shasteusis) ', M. Neivherryi, Lea, 1860; M. r^idenn^ 

 Reeve, 1860 ; Goniohasis Braytonii, Lea, 1862; G. Bairdiana^ 

 Lea, 1862; G. rubiginosa, Lea, 1863; G. plicifera, var. Oregon- 

 <?««?'«, Tryon, 1865; G. plicifera, \iiv. huUmoides, Tryon, 1865; 

 G. circumlineata, Tryon, 1865 ; 31. Californica, Clessin, 1882 ; 

 3[. [Goniohasis 'i) acutifilosa, Stearns, 1891 ; G. acutifilosa Siski- 

 youensis, Pilsbry, 1899 ; G. Kettleinanensis, Arnold, 1910. 

 Sliell of moderate size, attenuate-conic, whorls rounded, sutures 



moderately impiessed, peripliery sliowing no trace of a carina, aperture 



elliptical, outer lip slightly sinuate, and somewliat pioduced below; 



luibitat running streams and springs, infrequently in lakes. 



Columbia, Klamath, Fraser (locally), Nevada (locally), and Coast 



liange (locally) Systems. 



Pliocene : Kettleman Lake beds, California. 



Ambloxus tener (Hall). 



Ccritliium tenerum, Hall, 1845; C. nodulomm. Hall, 1845; Gonio- 

 hasis Carteri, Coiirad, 1869; G. columinaris, White, 1883, not 

 3Ielania tenera, ' Anth. MS.,' Ileeve, 1861 = A. Virginicus. 

 Shell similar to A. Virginicus, but the wliorls usually more 

 attenuate and less compressed, aperture but slightly sinuate ; habitat 

 apparently more or less lacustrine. 



Eocene: Wasach, Green lliver, and Bridger formations of Rocky 

 Mountains ; Truckee Lake beds, Nevada. 



Ambloxus Olequaensis, Arnold & Hannibal, n.sp. 

 PI. VIII, Fig. 27. 



Shell slender-conic, similar in general outline and size to 

 A. Virginicus, but more regularly elongate, with proportionally 

 longer whorls, straight-sided above, and bending in rapidly at the 

 suture somewluit after the manner of Pleurocera hitceniafa; sculptured 

 forms with vertical plications and spiral ridges and frills as in 

 A. plicifera; aperture deeply sinuate and slightly jiroduced below ; 

 habitat apparently lacustrine, at least in part. 



Altitude (estimated), 32 mm. ; breadtli, 9'5 mm. ; altitude of 

 body-whorl, 9 mm. 



Eocene: Local freshwater beds in T(>jon formation, Washington. 



I 



