EXPLANATION OF PLATE XXIII. 



Figs. 1-5. SCHIZOPHORIA SUBELLIPTICA (White & Whitfield) p. 162 



1-2. Views of two pedicle valves. (W. M., No. 14227.) 3. View 

 of a brachial valve, one of the cotypes. 5. View of a large 

 brachial valve, one of the cotypes. (U. M., No. 1349.) 

 Kindcrhook, bed No. 6, Burlington, Iowa. 



Figs. 6-19. SCHIZOPHORIA CHOUTEAUENSIS n. sp p. 163 



6-7. Pedicle and brachial views of a nearly perfect specimen. 

 8-11. Brachial. pedicle, lateral and posterior views of a small 

 but very perfect example. (W. M., No. 14226.) 

 Chontcau limestone, Providence, Missouri. 



12-16. Brachial. pedicle, lateral, anterior and posterior views of a 

 nearly perfect specimen. (W. M., No. 9689.) 



Choutcau limestone, Pettis County, Missouri. 

 17-19. Brachial, pedicle and posterior views of a nearly perfect 

 shell with much more depressed pedicle valve than usual. It 

 is possible that this specimen should not be referred to this 

 species. (W. M., No. 8572.) 



Choutcau limestone, Green County, Missouri. 



Figs. 20-45. CAMAROPHORIA BISINUATA (Rowley) p. 172 



20-24. Pedicle, brachial. lateral, anterior and posterior views of a 

 slightly compressed but very perfect internal cast. 25-29. 

 Similar views of another very perfect internal cast. The me- 

 dian septum is shown clearly in both of these specimens, that 

 of the brachial valve less clearly. (W. M., No. 9108.) 



Residual chert, Springfield, Missouri. 



30-33, 34-37, 38-41. Pedicle, brachial, lateral and anterior views of 

 three very perfect specimens, metatypes. Fig. 39 shows clearly 

 the median septum of the brachial valve where the shell has 

 been exfoliated. (R. R. R.) 



Burlington white chert, Louisiana, Missouri. 



42-45. Pedicle, brachial, lateral and anterior views of a very per- 

 fect specimen referred to this species. (W. M., No. 13929.) 

 Kcokuk limestone, Warsaw, Illinois. 



Figs. 46-51. CAMAROPHORIA EXPLANATA (McChesney) p. 173 



46-47. Pedicle and brachial views of a sulphur cast of the holotype. 

 (W. M., No. 12424.) 



Chester group, Illinois. 



48-51. Pedicle, brachial, lateral and anterior views of a very per- 

 fect specimen. (W. M., No. 7726.) 

 Chester group, Chester, Illinois. 



Figs. 52-60. CAMAROPHORIA HAMBURGENSIS Weller p. 170 



52-55. Brachial, pedicle, lateral and anterior views of a small but 

 nearly perfect specimen. 56-58. Views of three detached 

 brachial valves. 59-60. Views of two detached pedicle valves. 

 (W. M., No. 13937.) 



Hamburg oolite (Kindcrhook), Hamburg, Illinois. 



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