PLATE 44. 



Page. 



Fig. 1. Campeloma multilineata 586 



I, a. A dorsal view of type-specimen, which has the lip broken. 



1, 6. An aperture view of same. 



Fig. 2. Viviparus trochiformis 580 



2, a. A dorsal view of type-specimen. 



2,6. An aperture view of same. [Lip partly broken away.] 



2, c. A dorsal view of a larger individual, with spire proportionally more produced and body- 



volution less angular. 

 2, a". A small specimen, with body- volution distinctly angular. 



2, e. Finer surface-markings, magnified. 



Fig. 3. Viviparus Leidyi, var. formosus 580 



3, a. A dorsal side view. 



3, b. An aperture view, the lip being broken. 

 3, e. Surface-markings, magnified. 



Fir,. 4. Viviparus Leidyi 582 ■ 



A dorsal view of the type-specimen, the apex and much of the lip of which are broken 

 away. 



Fig. 5. Viviparus retusus 578 



5, a. A side view of the type-specimen, showing the obliquity of the outer lip. [The bluut- 



ness of the apex of the spire is not well represented in this and the other figures.] 

 5, 6. A dorsal view of the same. 

 5, c. An aperture view of a slightly larger specimen. 

 5, d. A dorsal view of a smaller specimen. 



5, e. An aperture view of the last. 

 5,/. Surface-markings, magnified. 



Fig. 6. Viviparus Leai 577 



<>, a. An aperture view of the type-specimen. [Compare with 5, c, of the last species.] 



6, 6. An opposite or dorsal view of same. 

 0, c. The same view of another specimen. 



6, d. An aperture view of a smaller individual. ■ 



Fig. 1. Viviparus Raynoi.dsanus 584 



7, a. Dorsal view of type-specimen. 



7, 6. Aperture view of same. [Revolving-markings should be slightly indicated.] 



Fig. 8. Thaumastus limjlikormis 558 



8, a. Dorsal side of type-specimen. 



8, b. Aperture view of same; the thin inner lip being broken away above. * 



8, c. A dorsal view of a somewhat narrower specimen. 



8, d. An aperture view of same ; its thin iuner lip above the middle being broken away. 



Fig. 9. Planorbis planocon vexus '. 538 



9,0. An upper or right-side view of the type-specimen, which is mainly an internal cast. 



9, b. An aperture view of same. 



9, c. An under or umbilical view of same. 



Fig. 10. Acroloxus minutus 543 



Type-specimen, magnified about four diameters. 

 Fig. 11. Columna teres .' 555 



11, a. Type-specimen, dorsal view, natural size. 



11, b. The same, magnified. 



Fig. 12. Columna vermicula 556 



12,a. Type-specimen, natural size. 

 12,6. The same, magnified. 



FlG. 13. LlMNJEA (PLEUROLIMANiEA) TENUICOSTATA 534 



13, o. Dorsal view of type-specimen, natural size. 



13,6. The same, magnified. 



13, e. Body-volution of same, more highly magnified, to show surface-markings. 



N 



