PLATE VII. 



PAOF. 



Fig. 110 COCHLIODUS VAN HOF.XII, St. J. and W - 12 " 



1 a. MaxillaiT posterior tooth, left rauius, view from abo-vei l b do., inner margin; 

 lo do., outer margin; 1 d do., foreshortened view from anterior border; 

 1 e do., inferior surface. St. Louis, Alton. 111. Mr. W. C. Van Home. 



Fig. 2 a. Same form, right minus, anterior portion broken away, showing impres- 

 sion of Inferior surface in the limestone matrix. Same formation, 

 locality and collection. 



Fig. 3 a. Transverse coronal ridges of the maxillary medium series of left ramus, 

 upon a common basal support, seen from above, enlarged; 3 b do., from 

 the inner margin; 3 c do., outer margin; 3 d do., from the antero-lateral 

 border: 3 e do., showing the undivided inferior surface of the base. St. 

 Louis, Pella, Iowa. Mr. Van Home. 



Fig. 4 a, b, c. Inner, outer and profile views of a fore tooth of the maxillary median 

 or anterior series, enlarged. Same formation, locality and collection. 



Fig. 5 a, i), c. Similar views of another example of the same form, enlarged. Same 

 formation, locality and collection. 



Fig 8 a, b, c, d. Another specimen of the same form, seen from above, inner, outer 

 and profile views. Same formation, locality, and collection. 



Fig. 7 a. Mandible, with the teeth of the rami in natural position, as seen from 

 below; the specimen represented as discovered in the limestone matrix. 

 St. Louis; Alton, 111. Mr. Van Home. 



Fig. 8 a. Mandibular posterior and median teeth of the right ramus of the foregoing 

 specimen, seen from above. 



Fig. 9 a. The posterior tooth of left ramus of above example, seen from above; 9 b 

 do., profile outline from antero-lateral border. 



Fig. 10 a. Mandibular median tooth, associated with 9 a, seen from above; 10 b do., 

 profile and outline from postero-lateral border. 



COCHLIODUS LEIDTI, St. J. and W 127 



Fig. 11 a. Maxillary posterior tooth, right ramus, views from above. Chester lime- 

 stone; Chester, 111. Prof. Worthen. 



Fig. 12 a. Same form, left ramus, from above; 12 b do., from inner margin; 12odo. r 

 outer inrolled margin; 12 d do., foreshortened view from antero-lateral 

 border. Chester limestone; Evansville, 111. Dr. Hambach. 



Fig. 13 a, Maxillary median series of left ramus, seen from above; 13 b do., from inner 

 margin; 13 c do., outer margin; 13 d do., profile from antero-lateral bor- 

 der; 13 e do., inferior surface, showing basal support without transverse 

 sutures. Chester; Chester, 111. Prof. Worthen. 



Fig. 14 a. Mandibular posterior tooth, left ramus, a large, imperfect example, from 

 above. Chester limestone; Prairie du Long, 111. Prof. Worthen. 



Fig. 15 a. A smaller perfect example of same form, right ramus, viewed from above; 



15 b do., from inner margin; 15 c do., outer margin; 15 d do., from antero- 

 lateral border, foreshortened. Chester; Chester, 111. Mr. Van Home. 



Fig. 16 a. Mandibular median tooth, right ramus, view from above, outline restored; 



16 b do., from inner margin; 16 c do., outer inrolled margin; 16 d do., from 

 postero-lateral border. Chester limestone; Chester, 111. Prof. Worthen. 



COCHLIODUS OBLIQUUS, St. J. and W 125 



Fig. 17 a. Maxillary posterior tooth, left ramus, viewed from above, enlarged; 17 & do., 

 from the antero-lateral border; 17 c do., postero-lateral border. St. Louis 

 limestone; St. Louis, Mo. Mr. St. John. 



