PLATE 38. 



Fig. 1. 74. 7. ^Pleurotomaria umbilicata. " (Pag. 175.) 



1 a. Back of the shell, showing an elevated spire. 1 b. Front view, showing the aperture. 1 c. Base. 

 1 d. Top of the spire of a larger specimen. 1 e. Front view, showing a depressed spire. 1 /• Base. 

 1 g. Specimen from iVIineral Point, showing a greater elevation of the spire. 



Fig. 2. 226. 14. Pleurotomaria indenta. (Pag- 176.) 



Fig. 3. 227. 15. Pleurotomaria ambigua. (Pag. 176.) 



3 a. View of the back of the spire. 3 b. Front of the same, showing the aperture. 



Fig. 4. 228. 16. Pleurotomaria percarinata. (Pag. 177.) 



Fig. 5. 229. 6. Murchisonia bicincta. (Pag. 177.) 



5 a. Front view of a nearly perfect specimen, showing the form of the aperture. .5 b. Back view. 

 ■ 5 c. Front view of a specimen with the last volution broken otT behind the aperture. 



5 d- View of an imperfect specimen, showing the direction of the striae. 5 e. Enlarged view of the same. 

 5f. A smooth cast from crystalline limestone, scarcely preserving the upper carination in an obscure angle. 

 5 g. A large imperfect specimen, still preserving the striae upon the surface. 



5 h. A portion of the same enlarged. 



Fig. 6. 230. 7. MuECHisoNLi teicaeinata. (Pag. 178.) 



6 a. View of the back of the shell. 



6 b. Front view, showing the aperture, which is imperfect on the outer side. 



G c. A fragment apjiarently belonging to the same species ; but the stri^ are much better preserved, a'ld tlie 

 carina: sharply jjrojecting. 



Fig. 7. 231. 8. Murchisonia perangulata. (Pag. 179.) 



7 a. Back of the spire, showing six volutions. 1 b. A portion of the surface, with the stria? enlarged. 



Fig. 8. 232. 9. Murchisonia uniangulata. (Pag- 179.) 



