Plate 7. 
Page 
Figure 1. Pecten hcriciits Gould. 52 
Exterior of right valve. 
Arnold Tert. Pectens. 
2. Pecten hericius Gould. 52 
Exterior of left valve. 
Arnold Tert. Pectens. 
3. Pecten hindsii Carpenter. 53 
Exterior of left valve. 
Arnold Tert. Pectens. 
4. Pecten hindsii Carpenter. 53 
Exterior of right valve. 
Arnold Tert. Pectens. 
