PLATE 54. 
Page 
Fig. 1. Holopea subconica. 294 
In. View showing the aperture, which is represented with peristome too much thickened. 
1 b. The anterior side of the same. 
Fig. 2 & 3. IIolopea antiqua. 294 
2 a. A cast of this species of the ordinary size. 
2 b. A similar cast, which is a little more ventricose. 
3 a. A cast of a larger specimen. 
3 b. The anterior view of a larger individual. The apparent extension of the shell on the 
lower side is a misrepresentation by the artist. 
Fig. 4 & 5. IIolopea antiqua, var . pervetusta. 295 
4. A cast of this species. 
5. A specimen retaining the shell. 
Fig. 6 & 7. IIolopea? elongata. 295 
6. A section of a small individual shown on the worn surface of the rock. 
7. A larger specimen which preserves some remains of the columellar lip, the upper volutions 
being entire. 
Fig. 8. Loxonema attenuata. 296 
8. The posterior side of the cast, the aperture being filled with stone. 
Fig. 9 & 11. Loxonema fitchi. 296 
9. Anterior side of a cast which is flattened in that direction. 
11 a. A fragment of the same species from the shaly limestone. 
11 b. A similar fragment of a larger individual. 
Fig. 10. Loxonema? obtusa. 297 
10. A longitudinal section of a specimen of this species upon the worn surface of the rock. 
Fig. 12. Loxonema? comp acta. 297 
12. A specimen from which the shell is exfoliated, preserving thirteen volutions with the apex 
imperfect. 
Fig. 13. Loxonema planogyrata. 298 
13. The anterior side of the specimen, the apex of which, as represented in the figure, preserves 
no marks of volutions. 
Fig. 14. IIolopea danai. 295 
14. Anterior view of the cast of this species. 
Fig. 15 & 16. Murciiisonia extenuata. 298 
15. Copied from a figure of Mr. Conkad, which is cited as from the Tentaculite limestone of 
Fayetteville, Onondaga county. 
10. A much worn specimen, which is perhaps of the same species. 
Fig. 17. Murciiisonia minuta. 298 
17. Representations of the specimen, natural size and enlarged, from figures by Mr. Coxrad. 
Fig. 18 a - e . Spirorbis laxus. 349 
18 a. A fragment of stone, preserving numerous individuals of this species. 
18 b. The upper side of the spire of a specimen, greatly enlarged. 
18 c. The lower side, showing the round mouth and the umbilicus. 
18 d. A specimen in which the last volution is free (a common condition of the species). 
18 e. A specimen in which the apex is closely involved, and the remaining portions not con¬ 
tiguous. ( This is an extreme form, and rarely seen.) 
