PLATE LXXXII. 



IFignree 1-6, 10-13, IS, M, 23, -25, '26 by G. B. Simpson ; 7, U by E. Emmons ; 8, 9, H-17, l!i-v!l, 27-38 by K. P. Whmfielu.) 



Genus CCELOSPIRA, Hall. 



Page 136. 

 CcELOSPIRA HEMISPHERICA, Sovveihy. 



Figs. 1, 2. Exterioi-8 of two pedicle-valves ; showing the contour, character of plication and concentric 



strisE. 

 Figs. 3, 4. Exteriors of brachial valves. 



Clinton group. Western New York. 



C(ELOSPIRA PLICATULA, Hilll. 

 See Plate 52. 

 Fig. 5. ITie interior of a portion of the brachial valve ; showing the divided hinge-plate and median 

 ridge. X 2. 



Clinton group. fVayiie county. New York. 



Genus ATRYPINA, gen. nov. 



Page IRl. 

 AtRYPINA ClINTONI, sp. 110V. 

 See Plate 63. 

 Fig. 6. The exterior of a pedicle-valve. X 2. 



Clinton group. Front a boulder ; Western New York. 



Genus ANABAIA, Clarke. 



Page 141. 



Anabaia Paraia, Clarke. 



Fig. 7. An internal cast of the brachial valve ; showing the impression of the cardinal process and the 

 marginal elevation of the median fold. 



Middle Silurian. Hio Tromhltas, Brazil. 



Genus VITULINA, Hall. 



Page 138. 



ViTULINA PU8TULOSA, Hall. 



Fig. 8. The exterior of a pedicle-valve of an average 8i)ecimen. 

 Fig. 9. ITie exterior of a brachial valve. 



Fig. 10. Ventral side of an internal cast ; showing the impressions of the teeth, adductor luid diductor 

 muscles. X 2. 



Hamilton shales. Western New York. 

 Fig. 11. Ventral view of a preparation ; showing three volutions of the spiral cone which is dii'ected toward 

 the lateral margin of the shell. 



Hamilton shales. Alden, New York. 

 Figs. 12, 13. Interiors of brachial valves ; showing the cardinal process and low crural plates. 

 Middle Devonian. Ereri, Brazil. 



