PLATE XLI. 
PAOE 
Fig. 1. Pleukotoma (Hemipleurotojia) albida Perry 146 
1. Ventral view. Jones Wharf. 
Figs. 2, 3. Pleueotoma (Hemii'leukotoma) communis Conrad 147 
2. Ventral view of adult individual. Cove Point, 
3. Ventral view of young individual. Same locality. 
Figs. 4-6. Pleurotoma (HEMiPLEtRoxoMA) COMMUNIS Conrad var. pro- 
TocoMMUNis n. var 147 
4. Ventral view. Plum Point. Cornell University. 
5. Ventral view of larger specimen. Same locality. 
6. Dorsal view of young individual. Same locality. 
Fig. 7. Pleurotoma (Hemipleurotoma) choptankensis n. sp 148 
7. Ventral view. Jones Wharf. 
Figs. 8, 9. Pleurotoma (Hemipleurotoma) bellacrenata Conrad 148 
8. Ventral view of adult individual. Plum Point. 
9. Ventral view of young. Same locality. Cornell University. 
Figs. 10, 11. Pleurotoma (Hemipleurotoma) calvektensis n. sp 149 
10. Ventral view. Plum Point. 
11. Ventral view showing the other extreme in sculpture. Same 
locality. U. S. National Museum. 
Figs. 12a, 12b. Sukcula eugata Conrad 149 
12a. Ventral view. Jones Wharf. 
12b. Dorsal view of same specimen. 
Fig. 13. Surcula marylandica Conrad 150 
13. Ventral view. Plum Point. 
Fig. 14. Sukcula biscatenaeia Conrad 151 
14. Ventral view. St. Mary's River. 
Fig. 15. SuECULA engonata Conrad 151 
15. Ventral view. St. Mary's River. 
Pig. 16. SuECULA ROTIFERA Conrad 152 
16. Ventral view. St. Mary's River. 
Fig. 17. Surcula mariana n. sp 152 
17. Specimen from St. Mary's River. 
