PLATE 60. 
Page 
Figs. 1-4. Terebratula lens. 386 
1-3. Dorsal, ventral and prolile views of a specimen of the ordinary size and form. 
4. Dorsal view of a larger but somewhat distorted specimen. 
Figs. 5-10, 68. Terebratula sullivanti. 387 
5-7. Dorsal, ventral and profile views of a small specimen of the species, from Columbus, Ohio. 
8. Dorsal view of an imperfect specimen, from Cayuga, Canada West. 
9,10. Dorsal and ventral views of a large imperfect specimen, from the same locality as the last. 
68. Enlarged dorsal view of a specimen from Cayuga, C. W-, showing the reversed loop. This 
feature, so far as yet ascertained, is peculiar to this species, and may possibly be due to 
accident in the specimen examined. 
Figs. 11-16. Terebratula harmonia.. 388 
11. Dorsal view of a young individual. 
12. Ventral view of a larger and broader form, from Cayuga, C. W. 
13. The dorsal side of the same specimen cut down to show the loop. 
14-16. Dorsal, ventral and profile views of a more elongated specimen. This, and specimen 
fig. 11, are from the Falls of the Ohio. 
Figs. 17 -25, 66,67. Terebratula rcemingeri. 389 
17 -19. Dorsal, ventral and profile view of a large rotund form, from Hamburgh, N. Y., on the 
shore of Lake Erie. 
20, 21. Dorsal views of two specimens from New York, one of them showing an emargination 
in front, and the other rounded; enlarged to two diameters. 
22 - 24. Dorsal, ventral and profile views of a specimen from Michigan, showing a distinct emar¬ 
gination in front and a sinus on the ventral side; enlarged to two diameters. 
25. Dorsal view of another individual from Michigan, which is destitute of sinus or emargina¬ 
tion; enlarged to two diameters. 
66, 67. Ventral and profile views of the loop of this species; enlarged from a specimen, from 
Michigan. 
Figs. 26-28. Terebratula elia. 390 
26-28. Dorsal, ventral and profile views of the specimen described. 
Figs. 29-31. Terebratula jucunda. 390 
29-31. Dorsal, ventral and profile views of the specimen described. 
Figs. 32 - 37, 71. Terebratula linckl^seni var. ^418 
32. Dorsal view of a young shell of this species. 
33-35. Dorsal, ventral and profile views of a full grown shell. 
36, 37. Dorsal and profile views of a more gibbous form. 
71. Ventral view of the loop, showing the disconnection at the anterior extremities.. 
Figs. 38-44. Terebratula navicella. 391 
38-40. Dorsal, ventral and profile views of a large specimen of the species. 
41. Dorsal view of a smaller individual. 
42 -44. Dorsal ventral and profile views of a more slender specimen of the species. 
Figs. 45-48. Terebratula Ontario. 418 
45. Dorsal view of a round symmetrical specimen. 
46-48. Dorsal, ventral and profile views of a larger and slightly longer specimen. 
Figs. 49-65. Terebratula LiNCKLiENi. 397 
(This species referred with doubt to the Genus Cryptonella on page 397, has proved to be a 
Terebratula.) 
49. Dorsal view of a young specimen. 
50 - 52. Dorsal, ventral and profile views of a larger specimen. 
53 - 55. Dorsal, ventral and profile views of a more gibbous specimen, which is much thickened. 
on the front margin. 
56, 57. Ventral and profile views of a small and very gibbous individual with strong varices of 
growth. 
58, 59. Dorsal and ventral views of a young individual having a much broader or less elongated 
form than usual. 
60. Dorsal view of a larger specimen of the same form with the last. 
61-63. Dorsal, ventral and profile views of a full grown specimen of the broad form. 
64, 65. Dorsal and ventral views of a cast of this species, showing the muscular lines and also 
the cavities near the beak left by the removal of the dental lamellae. 
Figs. 69, 70. Terebratula simulator. 39J 
69. Dorsal view of a specimen which has been cut to show the loop; enlarged to two diameters. 
70. Profile view of the loop, showing the long crural processes; enlarged. The connexion at 
the anterior end is theoretically restored, but may have been connected during life by a 
ligament only. 
