WEST AMERICAN PYRAMIDELLID MOLLUSKS. 193 



KEY TO THK SPECIES OF THE SUBfiENUS EVALEA. 



Shell umbilicated. 



Spiral sculpture consisting of incised lines only. 



Columellar fold on the middle of the columella nunivakensis, p. 194. 



Columellar fold decidedly posterior to the middle of the columella. 

 Spiral sculpture strong. 



Shell thick and robust HI Ms nooensis, p. 195. 



Shell thin and delicate. 



Shell small, adult 4.1 mm. long tillamookensis, p. 195. 



Shell larger, adult 5.5 mm. long esilda, p. 196. 



Spiral sculpture very fine. 

 Shell very broadly conic. 



Sutures very strongly contracted aleutica, p. 196. 



Sutures not strongly contracted kadiahensis, p. 197. 



Shell elongate-conic. 



Summit of the whorls narrowly tabulated herilda, p. 197. 



Summit of the whorls not tabulated. 

 Sutures strongly contracted. 

 Whorls well rounded. 



Shell very small, adult 1.6 mm. long. tenuis, p. 197. 



Shell larger, adult 3 mm. long valdezi, p. 198. 



Whorls flattened in the middle riemo, p. 198. 



Sutures not strongly contracted : io, p. 199. 



Shell ovate pratoma, p. 199. 



Spiral sculpture consisting of fine incised lines and slender raised lirations, the 

 latter stronger than the spaces between the striations. 



Spiral lirations confined to the base septentrionalis, p. 200. 



Spiral lirations on spire and base capitana, p. 200. 



Shell not umbilicated. 



Incised spiral lines strong over the entire surface of the shell. 

 Periphery of the last whorl subangulated. 



Spiral sculpture uniform jewetti, p. 201. 



Spiral sculpture consisting of fine and strong striations . . Anflata, p. 201. 

 Periphery of the last whorl well rounded. 



Shell elongate-conic columbiana, p. 202. 



Shell elongate-ovate unalaskensis, p. 203. 



Incised spiral lines strong on the early whorls and much finer on the later turns. 

 Shell very broadly ovate. 



Shell with incised lines and raised lirations on the last whorl, atossa, p. 203. 

 Shell with incised lines only. 



Outer lip decidedly expanded anteriorly obesa, p. 203. 



Outer lip evenly curved lucasana, p. 204. 



Shell elongate-ovate. 



Shell white, semitransparent. 



Adult shell 4.8 mm. long phanea, p. 204. 



Adult shell 3.3 mm. long phanella, p. 205. 



Shell not white nor semitransparent. 



Incised spirals upon the second whorl 7 santarosana, p. 205. 



Incised spirals upon the second whorl IF,. ..tenuisculpta, p. 206. 

 Incised spiral lines only moderately strong. 



Periphery of the last whorl very strongly angulated angularis, p. 207. 



Periphery of the last whorl subangulated. 



Posterior angle of aperture with weak notch socnrroensis, p. 208. 



Posterior angle without notch. 



Adult shell 4.5 mm. long... donilla, p. 208. 



Adult shell 3 mm. long cali/ornica, p. 208. 



