PLATE 43. 



Fig. 1 « - m. Rhynohonella venteicosa. 238 



1 a, b. c. Dorsal, ventral, and profile views of a specimen of ordinarj- 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. fc. Profile and front views of an extremely ventricose specimen. 

 1 /. Dorsal view of a more elongate form than usual. 



1 m. Knlargcment of the plications, showing impressed lines and strong striae in front of the 

 shell. 



Fig. 2 a - 1. Rhynohonella campbellana. 239 



2 o - e. Ventral, dorsal, profile, and front views of young specimens. 

 2/, 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 fc. Enlargement of several plications of the front of the ventral valve. 

 2 /. A cast of the ventral valve [ the letter / should be Z ] . 



Fig. % a- I. Rhynohonella nobilis. 240 



3 o, 6. A young siwcimen with a scarcely defined sinus. 



8 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 t, k. Dorsal and front views of the largest and most ventricose form that has been observed. 

 3 Z [ by error marked 3 6]. A cast of the ventral valve of this species. 



