1922] Fauna from the Eocene of Washington 45 



Pachychilus drakei Arnold and Hannibal has the pattern of sculpture similar 

 to that of this form, but the plications in that species are fewer. Arnold and 

 Hannibal's species were collected at the same locality as G. hannibaii n. sp. 



This species as well as Ambloxus olequahensis Arnold and Hannibal has 

 been determined by Dr. H. A. Pilsbry as belonging- to the genus Goniobasis of the 

 group G. plicifera Lea. 



Dimensions. Altitude 18 mm. (measurements taken of 5 whorls) ; width 

 of body whorl 7 mm. 



Occurrence. At localities 315, 316, and 317 (University of Washington 

 Palaeontological Collection) on Olequah Creek, near Vader, Lewis County, Sec- 

 tion 20, Township 11 North, Range 2 West. 



GONIOBASIS OLEQUAHENSIS n. sp. 

 Plate XI, Figure 13 



Description. Shell small and elongate; whorls five or six; whorls rounded; 

 suture distinct, appressed; surface ornamented with eleven longitudinal, prom- 

 inent ribs with interspaces three times the width of the ribs ; the ribs are curved 

 and increase in size at the middle point of the whorl where they 

 tend to become pointed; on the whorls of the spire the longitudinal ridges 

 may be crossed just above the suture with one prominent revolving rib ; on the 

 body whorl there are about eight pronounced revolving ribs which occur on the 

 lower half of the whorl and extend to the base of the whorl ; aperture ovate, 

 entire ; fine microscopic growth lines may be seen between the longitudinal ridges. 



Dimensions. Altitude 9 mm. ; width of body whorl 4 mm. 



Occurrence. At locality 315 (University of Washington Palaeontological 

 Collection) at the dam below railroad bridge on Olequah Creek about one-third 

 of a mile below the junction of Olequah and Stillwater Creeks, near Vader, 

 Lewis County, Section 32, Township 11 North, Range 2 West. 



