PLATE XCI— Continued. 



Leptodesma Maclukii. 



Page 22S. 

 See Plate 25. 

 Fig. 13. A large left yalve of this species. This figure is given in correction of tig. 13, plate 25. 



Chemung group. Near Smethport, Pa. 



Fig. 14. The right valve figured on plate 25, tig. 8, redrawn to correct the outline. 



Chemung group. Xcar Smethport, Pa. 



Leptodesma quadratum. 



Page 233. 

 Fig. 15. The left valve described. 



Chemung group. Steuben Co., N. Y. 



Leptodesma propinquum. 



; Page -231. 

 Fig. 16. A nearly entire left valve, showing the form and characters of the species. 



Chemung group. Maw-field. Pa. 

 Fig. 17. A similar right valve. 



Chemung group. Mansfield, Pa. 



Leptodesma Phaon. 



Page 230. 

 Fig. 18. A left valve of this species. 



Chemung group. Munsjbhl, Pa. 



Leptodesma Lichas. 



Page 232. 

 See Plate 21. 

 Fig. 19. A small left valve. 



Chemung group. Stevhen Co., N. Y. 

 Fig. 20. Tin- left valve figured on plate 21, tig. 37. redrawn to con-eel the outline. 

 Chemung group. PMlipsburg, N. Y. 



f — Mytiloidea. 

 Leptodesma acutieostrum. 



Page 234. 

 Fig. 21. The left valve described, showing the form of the body and the acute anterior end. 

 Chemung group. Warren, Pa. 



Leptodesma mytiliforme. 



Page 235. 

 See Plate 25. 

 Fi«\ 22. The right valve figured on plate 25, tig. 7, redrawn to correct the outline and the form of the body. 

 Fig. 23. A small left valve. 



Fig. 2-1. A view of left valve given in correction of lig. 11, plate 2.1. 

 Fig. 25. Two left valves as preserved on the surface of a piece of sandstone. 

 Chemung group. Road from Olean to Smeikport, Pa. 



