PLANORBIS. 219 
PLANOBBIS. 
SYNONYMY AND REFERENCE TO 
PLATE 7. 
Fig. 
1—3. PL. opERcuLARIS, Gould. Proc. Bost. 
Soc. ii, 212, 1847. 
Binney, 1. c. 125. No, 19, 
4—6. PL. vERMIcULARIS, Gould. Proc. Bost. 
Soc. ii, 212, 1847. 
Binney, 1. c. 128. No. 21, 
7—9. Pu. CEnrervitiensis, Tryon. This 
work, p. 210. No. 24, 
PL, pARvus, Say. Hald. Monog. p. 27, 
t. 4, f. 19—23. 
10. = Pl. Billingsii, Lea. Philad. Proc. iii, 
1864. 
Observ. xi, 115, t. 23, f. 72. No, 26, 
(66) 
