IPE AMD 1B SO OW UIE 
MErENGONOCERAS, PLACENTICERAS. 
Page. 
Figs. 1-2. Metengonoceras acutum Hyatt.......-------------------+- 222207 -e rrr recess cscs: 184 
Fig. 1. Ventral view of type specimen. 
2. Septum of same, * 2. 
Elm Fork, Dallas County, Tex., probably Eagle Ford shales, Upper Cretaceous. 
Coll. Mus. Comp. Zool., Cambridge. 
Fis. 3-14. Metengonoceras dumbli (Cragin) ..---.-------------------+-+2+2-2- rrr 2 2c rrrrrrse 185 
Figs. 3,4. Lateral and ventral views of specimen described. 
5. Section of same. 
6. Inner whorls of fig. 5, enlarged. 
7. Center of same, still more enlarged, showing antisiphonal lobe, the inner- 
most whorls having dropped out. 
8. Section of whorl in neanic stage, < 10. 
§. Adult lateral suture, X 23. 
10. Last lateral suture, < 23. 
11. Dorsal suture continuous with fig. 9, enlarged. 
12. Dorsal suture one-fourth volution older than fig. 11, enlarged. 
13. Lateral and part of dorsal suture of neanic stage, x 18. 
14. Dorsal suture of somewhat later substage than fig. 13, enlarged. 
Four miles east of Whitesboro, Tex.; Eagle Ford shales, Upper Cretaceous; Coll. 
U.S. Geol. Surv. ; i 
Fras. 15-17. Placenticeras syrtale (Morton) ....----------------+-----------+-+++-+------------ 205 
Fig. 15. Suture of the type in Coll. Acad. Nat. Sci. Phila. 
16. Lateral suture of var. halei, Coll. Bost. Soc. Nat. Hist., No. 85 
17. Dorsal suture of older part of same volution as fig. 16. 
Greene County, Ala.; Eutaw beds (2), Upper Cretaceous. 
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