PLATE 43. 
la- m. Riiynchonella ventricosa. 
1 a, b. c. Dorsal, ventral, and profile views of a specimen of ordinary size and proportions. 
1 d. Front view of the same specimen. 
1 e,f. g, h. Dorsal, ventral, and profile views of more ventricose specimens. 
1 i, k. Profile and front views of an extremely ventricose specimen. 
1 1. Dorsal view of a more elongate form than usual. 
1 hi . Enlargement of the plications, showing impressed lines and strong stria? in front of the 
shell. 
2 a - l. Rhynchonella campbellana. 
'la - e. Ventral, dorsal, profile, and front views of young specimens. 
If.h. Dorsal and profile views of an individual of full size. 
2 g, i. Ventral and front views of an individual of full size, which is broader in the middle 
than usual. 
2 k. Enlargement of several plications of the front of the ventral valve. 
2 f. A cast of the ventral valve [ the letter f should be / ]. 
3 a - l . Rhynchonella nobilis. 
3 a, b. A young specimen with a scarcely defined sinus. 
3 c, d, e.f. Dorsal, ventral, front, and profile views of an individual of medium size. 
3 g, h. Dorsal and front views of a larger and more gibbous specimen. 
3 i, k. Dorsal and front views of the largest and most ventricose form that has been observed. 
3 l [ by error marked 3 6], A cast of the ventral valve of this species. 
