PL^VTE XVII. 



Fig. 1. Couriui-A Engki.manni 174 



1. A largo sprciraeu, with a part of posterior extremity broken ofl'. 



1 a. The original typical specimen, enlarged two diameters. 



Fig. 'i. CoUBULA PYRIFORMIS 170 



2. A side view of a rather distinctly ribbed specimen, with a portion of its posterior 



extremity broken away, natural size. 



2 a. The original typical specimen, smooth variety. 



2 b. An anterior view of same, showing its very nearly eqnivalvo character. 



2c. A very large, irregularly ribbed specimen, with the posterior extremity slightly 



broken. 

 2d. A dorsal view of another specimen, slightly distorted by compression. It shows the 



posterior dorsal furrow and the angle along the margin of each valve. 



Fig. 3. LlMN^.A SIMIllS 191 



:j. A dorsal view, show ing aperture, enlarged two diameters, 

 iirt. An opposite view of same. 



Fig. 4. LlMN^A VETL'STA 191 



4. A dorsal view, natural size. 



4 a. The same, somewhat enlarged. 



4 6. An opiJosite view of same, enlarged. 



Fig. f>. LlMN^A NrriDULA 181 



5. Dorsal view, enlarged two diameters. [Inner lip not well shown.] 



5 a. An opposite view of same. 



Fig. 6. Rh YTIPHOROS PRISCUS 175 



6. View of dorsal side (type-specimen). 



6n. An opposite view of same, showing the narrow aperture, with a part of the lip 

 broken away. 

 Fig. 7. GONIOBASIS SlMP.SONl 193 



7. One of the typical specimens, natural size, with apex broken away. 

 7 0. A specimen without regular costa. 



7 b. An opposite view of same. 

 7 c. A nearly smooth specimen. 

 7rf. A costate aud slightly nodose specimen, enlarged about two diameters. 



Fig. 8. Melania? sculptims 195 



Side and aperture view, enlarged about two diameters. 



Fig. 9. Mei.axia ? suBSCULPTii.is ; perhaps only a variety of last 196 



Side and aperture view, about two diameters. 

 Fig. 10. Carinifex (Vorticifex) Tryoni 188 



10. Side and aperture view, natural size. 

 10 a. View of upper side of same. 



10 b. Under view of same. 



10 c. A young, strongly costate specimen, with the apex- much depressed, being the type 



of the var. concava. 

 Fig. 11. CAitiNiFEX (Vorticifex) Binneyi 187 



11. Side and apcrlure view, natural size. 



1 1 a. View of upper side of same. 



Fig. 12. ANCYLU.S UNDULATUS 186 



12. A medium-sized specimen, natural size, dorsal viiw. 

 12 n. .\n outline lateral view of same. 



12 6. An outline lateral view of a larger specimen, natural size. 



