182 CLASS III. GASTEROPODA. ORDER VII. PECTINIBRANCHIATA. 
the basal canal is not developed to any length, nor are they ever armed 
with spines or tubercles. Some of the Cancellariz resemble the Nasse 
a little in their general form, but they may be always distinguished from 
these by the plaits on the columella. 
The shell of Cancellaria may be described as being oval, and variously | 
ribbed or reticulated on the outside, the last whorl being somewhat ven- | 
tricose, and often forming a large umbilicus; the columella, which is 
strongly marked with a greater or less number of plaits, ends in a short, 
sometimes posteriorly recurved canal ; and the aperture is ovate, or 
ovately oblong, with the lip somewhat expanded, generally denticulated, 
and either striated or sulcated within. 
Examples. | 
Pl. CCXXX. Fig. 10. 
CANCELLARIA INDENTATA, Sowerby, Proceedings Zool. Soc., 1832, p. 54. 
Pl. CCXXX. Fig. 11. 
CANCELLARIA BUCCINOIDES, Sowerby, Proceedings Zool. Soc., 1832. | 
Pl. CCXXX. Fig. 12. 
CANCELLARIA CLAVATULA, Sowerby, Proceedings Zool. Soc., 1832. 
Pl. CCXXX. Fig. 13. 
CANCELLARIA UNIPLICATA, Sowerby, Proceedings Zool Soc., 1832. 
Ph. .CCXXK... Fig, 14, | 
CANCELLARIA MITRIFORMIS, Sowerby, Proceedings Zool. Soc , 1832. 
Pl. CCXXX. Fig. 15. 
Canceciaria Tritonis, Sowerby, Conch. Illus. Cat., p. 2. no. 14. 
Pl. CCXXX. Fig. 16 and 17. 
CANCELLARIA GRANOSA, Sowerby, Conch. Illus. Cat., p. 2. no. 15. 
