OF CONCnOLOQY. 2T 



104. G. silicula, Gonld. Figs. 150, 151. Slender, nearly 

 cylindrical ; spire elevated, suture deeply impressed ; whorls 

 6 — 8, well rounded, with numerous obsolete fine revolving 

 strise, the upper ones longitudinally plicate. Dark chestnut- 

 color, sometimes with two bands. Oregon. 



Fig. 151 represents O. Shastaensis, Lea. 



lO-la. G. rudens, Reeve. Fig. 152. Slender cylindrical, 

 somewhat thick; whorls well rounded, spirally closely striated, 

 the first few strongly plicate. Dull olive. Oregon, Cal. 



105. G. nigrina, Lea. Fig. 153. Small, conical, rather 

 thin ; spire elevated, suture well impressed ; whorls 6 — 7, con- 

 vex, the first few faintly plicate, the last whorl striate below. 

 Nearly black, dark purple within. Oregon, Cal. 



106. G. rubiginosa, Lea. Fig. 154. Elevated, sub-cylin- 

 drical, rather thin ; spire sub-attenuate, suture very much im- 

 pressed ; whorls 7, convex, carinate, the first ones obscurely 

 plicate; body whorl angled and flattened on the periphery, 

 with a raised line above and below. Reddish, obscurely 

 banded, light reddish within. Oregon. 



107. G. Bairdiana, Lea. Fig. 155. Somewhat drawn out, 

 rather thick ; spire acute, suture impressed ; whorls 8, slightly 

 convex, the first few closely and distinctly plicate; aperture 

 small, ovate. Dark brown, whitish within, and single banded. 

 Oregon. 



d. Shell angulate. 



108. G. trochiformis, Conr. Fig. 156. Short conical, 

 turrited, babylonic. ventricose; spire short, suture well im- 

 pressed; whorls 6, angulated, flat-topped, each with two promi- 

 nent spiral lines ; periphery of body whorl carinated ; base 

 flattened. N. Ala. 



109. G. cristata, Anth. Figs. 157, 158. Rhomboidal, 

 strongly carinate, thin; spire short conical, suture slightly im- 

 pressed ; whorls 5, flat, shelving, very strongly angulate and 

 carinate in the middle. Horn-color, sometimes banded. Ala. 



110. G. cruda, Lea. Fig. 159. Sub-fusiform, rather thin, 

 shining; spire obtuse, suture slightly impressed ; whorls flat- 

 tened above, the last rather large and angulate in the middle ; 

 aperture large, rhomboidal. Dark brown, obscurely banded, 

 brown within. Tennessee River. 



111. G. Whitei, Lea. Fig: 160. Fusiform, thick, very 

 much inflated; spire obtusel}'' conical, suture slightly im- 

 pressed ; whorls 5, flattened above, the last ventricose ; aper- 

 ture large, widely rhomboidal. Bright yellowish-brown, gen- 

 erally 3-banded. Qeo. 



