PLATE XIX. 



Ctclonema Doris. 



I'age S4. 

 Rg. 1. An exaiiiiile of this 8i>ecie8 fi-ora the Schohaiie (fi-it, Schoharie, N. Y. 



Pleurotomaria Hebe. 



Page 68. 

 Flffs. 3-4. Summit, front and basal views of a specimen nearly denuded of shell, but showing: the g-enei-al 



form and to some extent the 8urfa<te charactei-s. The apjiearance of a callus covering the 



umbilicus is due to the fracture of the solid part of the columella. 

 F!g8. 5, 6. The opjK>site 8i<le8 of a specimen retaining a portion of the shell and showing sui-face cbai-acters. 

 tig. 7. A lai-ger si>ecimen nearly denuded of shell. 



Pleurotomaria sulcomaroinata. 

 Pueress. 

 Fig. 8. The upper side of a specimen. Fi-om the Falls of the Ohio. 

 Kgs. 9-11. Tlii-ee views of a specimen of the usual size as known in the Hamilton gi-oup of New York, 



retaining the shell and surface cliaractei-s. 

 Fig. 12. Enlargement to two diametcre of a snuiU, iinpei-fect specimen, with surface features strongly marked. 



Hamilton group, Pi-att's Falls, N. Y. 

 Figs. 13, 14. Two views of a specimen enlarged to two diametei-s, showing the more distinct surface striae. 



From the Hamilton gi"oup, Delphi, N. Y. 

 Fig. 16. A large internal cast refen-ed to this species. Hamilton gi-oup at Cumberland, Md. 

 Fig. 16. An internal cast. From the Hamilton gT(;>up near Deli)hi, N. Y. 

 Fig. 17. A small specimen, a partial cast, enlarged to three diametei-s. From the Hamilton group near 



Delphi, N. Y. 



Pleurotomaria delioatula. 



Page 70. 

 Figs. 18, 19. Two views of a specimen with shell, in part, and showing the surface characters. 



Pleurotomaria rotalia. 



Page 71. 



FIgB. 20, 21. Two views of a specimen of usual form and size, enlarged to four diametei-s. Fig. 21 shows 

 the band on the periphei-y. 



Fig. 22. The largest individual found, enlarged to three diameters, showing some modifications in the band 

 bortlering the suture. 



Figs. 23, 24. Ba«al views of two specimens, showing a slight vai-iation in the foinn and size of the callus sur- 

 rounding the umbilicus. 



Fig. 25. Lateral view of a large internal cast for compaiHson with the small specimens of P. sulcmnargliiata 

 which are of similar size and condition as in fig. 17. 



