ACADEMY OF SCIENCES. 97 



^ 1. Columellar lip strongly twisted, appressed, leaving little or"no umbili- 

 cal fissure behind it. 

 f Diameter not over half of length. 



I Outline ovate-lanceolate, whorls very oblique. Rarely malleated. 



13 gyriua Say. Wh. 5-6, mouth .55 of length, 1 to 3 lip- bands; diam. 

 0.20 to *0.40, alt. 0.50-*0.90. 



14 vi rgi n ea Gld. Wh. 5-6, mouth .60 of length, lip rarely thick ; diam. 

 *0.30-0.60, alt. *0.60-0.75. 



15 venusta Lea. Wh. 4-5, mouth .70 of length, spire short, lip thick ; 

 diam. *0.26-0.30, alt. 0.55-0.70. 



Var. hordacea Lea. Wh. 5, mouth .60 of length, lip thick, darker ; 



diam. *0.13, alt. *0.27. 

 f f Diameter half to two-thirds of length. 



J X Outline acute oval, whorls not very oblique. Sometimes malleated. 



16 Carltonii Lea. Wh. 5-6, thick, mouth .70 of length, 1-3 lip-bands ; 

 diam. 0.35-0.55, alt. 0.50-1.00. 



17 G a b b i i Tryon. Wh. 6, mouth .60 of length, inner lip expanded ; diam. 

 0.25-*0.50, alt. 0.40-*0.90. 



Var. Traskii Lea. Wh. 6, mouth .70 of length, thicker and darker ; 



diam. 0.35-*0.45, alt. 0.60-*0.76. 

 Var. occidentalis Tryon. Wh. 5-6, mouth .70 of length, columella 



notched flnteriorly ; diam. *0.42, alt. 0.70. 

 Vai\ D'Orbignyana Lea. Wh. 5, mouth .75 of length, striped ; diam. 



*0.32, alt. *0.55.(=.s;nata Lea.) 

 Var. sparsestriata Tryon. Wh. 5, mouth .65 of length, lip thin, stripes 



few ; diam. *0.28, alt. *0.48. » 



18 Blandii Lea. Wh. 4-5 (usually eroded), mouth .75 of length, diam. 

 *0.30, alt. *0.48. 



Var. distinguenda Tryon. Wh. 4-5, acute, mouth .65 of length, lip 



thin ; diam. *0.28-0.35, alt. *0.52-0.60. 

 (^l==Grosvenorii Lea. Wh. 5, spire longer; diam. *0.18, alt. *0.30. 



(Prior name.) 

 q'i=Nuttalii Lea. Wh. 4, mouth .60 of length; diam. *0.27, alt. 



*0.40. (Prior name.) 



19 triticea Lea. Wh. 4, mouth .75 of length, heavy, color dark, diam. 

 *0.14-0.20, alt. *0.27-0.35. (Nearest to heterostropha.) 



Q. Var. Cooperii Tryon. Wh. 3-4 (eroded), mouth .75 of length ; 

 diam, *0.18, alt. *0.32.' 



20 malleata Tryon. Wh. 5, mouth .65 of length, malleation strong; 

 diam. *0.25-0.32, alt. *0.45-0.55. 



Q? Var. parva Lea. Wh. 4, mouth .65 of length, smooth, lip thin ; 

 diam. *0.11, alt. *0.19. 

 XXX Often very fine revolving grooves. 



21 diaphana Tryon. Wh. 5, mouth .65 of length, yellowish, thick; 

 diam. *0.28-0.32, alt. *0.50-0.55. 



Var. politlssima Tryon. Wh. 5, mouth .60 of length, spire shorter, lip 

 thin ; diam. *0.26, alt. *0.45. 



