16 SYSTEMATIC ARRANGEMENT 



central tooth tridentate ; lateral with one basal elongated lobe, and 

 one terminal. The teeth of the females are perhaps rather the 

 largest. 



Lingual membrane of Cominella ?, from the Cape of Good 



Hope, linear elongate, transparent. Teeth 1 • 1 • 1, transparent, the 

 older one yellow ; central transverse, band-like, as broad as the 

 space between the lateral teeth ; front edge straight, with five small, 

 nearly equal toothlets in the middle ; the hinder edge rather concave 

 towards the front ; lateral teeth broad, front edge of the lower part 

 with three very unequal, acute lobes near the base, the middle lobe 

 largest ; the outer hinder angle rather produced ; the terminal lobe 

 large, acute, curved. 



Lingual membrane of Cominella ? is elongate, linear, trans- 

 parent ; older teeth yellowish. Teeth 1 ■ 1 • 1 ; central band-like, 

 transverse, not so broad as the space between lateral teeth ; front 

 edge nearly straight, with three nearly equal, large, conical teeth in 

 the middle ; hinder edge bent in the greater part of its length, 

 rounded at the hinder end ; lateral teeth with a large curved process 

 on the inner edge of the base and a much larger one at the end ; the 

 outer hinder angle rather produced. 



e. Nassina. Operculum ovate, serrated on the outer edge; foot 

 niched behind. 



15. Bullia. 



Shell ovate or turrited ; whorls smooth ; mouth ovate ; lips 

 simple ; hinder part of inner lip thickened, making a callous band 

 on the suture. Eyes none. Foot very large, expanded, square, 

 with two small lobes behind. Operculum small, ovate ; outer edge 

 toothed. 



1. B. kevigata, t. 20. f . 2, 3 ; Adams, Gen. Moll. t. 12. f. 3. 



2. B. achatina, t. 20. f. 1. 



3. B. Cochlidium, t. 98. f. 9. 



4. B. globosa, t. 98. f. 10. 



16. Nassa. 

 Shell ovate ; spire short ; whorls convex, waved, rarely variced ; 

 mouth moderate. Eyes distinct. Foot moderate, truncated and 

 tentaculated in front, nicked behind. Operculum moderate, serrated. 



1. N. coronata, t. 21. f. 2. 



2. N. arcularia, t. 98. f. 14, t. 21. f. 1, t. 102. f. 11, t. 21. f. 9, 10. 



3. N. olivacea, t. 21. f. 6, t. 85 a. f. 2, var. f. 6. 



4. N. gemmulata, t. 85 a. f. 7. 



5. N. crenulata, t. 85 a. f. 3. 



6. N. xanthostoma, t. 85 a. f. 5. 



7. N. Isabella, t. 98. f. 12. 



8. N. dentifera, t. 98. f. 11. 



9. N. riparium, t. 97. f. 1. 

 10. N. Thersites, t. 21. f. 3. 



