106 ARCHACHATINA. 



II. Shell dextral, surface even. 



a. Moderately solid, opaque, interior and columella 

 lilac or purple: exterior olivaceous, indistinctly 

 marked or closely streaked ; the early whorls usually 

 pink. 



b. Shell large, length more than 100 mm.; thick 

 and solid ; lip somewhat expanded. 



c. Aperture purple; shell ventricose, 125x87 

 to 117 x 77 mm. ventricosa, no. 6. 



cc. Aperture bright pink within, lip white- 

 edged; 117 x 70 mm. splendida, no. 9a. 

 bb. Shell less thick, smaller; lip not expanded. 



c. Last whorl very smooth ; streaked with 

 close, straight rufous streaks, often coale- 

 scent; aperture lilac, the lip not dark- 

 bordered within ; length 40 mm. 



rhodostoma, no. 9. 



cc. Last whorl decussate above ; aperture vio- 

 let or purple, the lip dark-bordered with- 

 in; 73x43 to 89x56 mm. 



purpurea, no. 7. 



ccc. Last whorl decussate above; aperture 

 lilac ; 60x32 mm. porphyrostoma, no. 8. 

 aa. Rather solid; aperture white or nearly so inside. 



1). Columella white, very concave; lip expanded and 

 thickened within ; length 100-130 mm. 



marginata, no. 2. 

 bb. Columella red or purple. 



c. 105 x 55 mm. ; solid, olivaceous-buff. 



grevillei, no. 5. 



cc. 101 x 50 mm. gracilior, no. 2a. 



ccc. 65 x 35 mm. ; thin, smooth, yellowish with 

 narrow streaks or maculate; columella 

 orange flesh-colored. ovum, no. 3. 



cccc. 84 x 52 mm. subsuturdlis, no. 2b. 



ccccc. 77x40 mm. Solid with broad dark 

 stripes, confluent below; columella rose- 

 tinted below cumin gi, no. 4. 



