PLATE X(;i— Coiitiimod. 



Lkitodesma Maclurii. 



Pago 228. 

 See Plate 25. 

 Fip. i:i. A \iirij;ii left .valve nf tlii.s species. This ti^rnre is f^iveii in correction of ti^. 18, plate 25. 



Chemung- group. Near Smetliport, Pa. 



V\g. 14. The i-ig-ht valve tig-iired on plate 25, tig. 8, i-edrawn to coi-rect the outline. 



Chemung group. Near fiinethport. Pa. 



LePTOUESMA gUADKATUM. 

 Page -233. 

 Fig. ir>. Till' left valve described. 



Chemung group, fiteuben Co., N. Y. 



Leptodesma PROPINQOUM. 



IPagu Ail. 

 Fig. l(i. A nearly entire left valve, showing the fonu .uid cliararters of the .species. 



Chemnng group. Mansfield, Pu. 

 Kig. 17. A similar right valve. 



Chemung group. Manxfmld. Pu. 



Leptodesma I'haon. 



Page 230 

 Fig. IS. .\ li'ft valve- (if this species. 



Chemung grouji. Man-tfield, Pa. 



Leptodesma Liciias. 



Page 232. 



.See Plate 21. 

 Fig. li". A small left valve. 



(Chemung group, fiteuhen Co., N. ¥. 

 Fig. 20. The li-ft \alve figured on plate 21, tig. 37, redi-awn to correct the outline. 



Chemung group. P/nlip.iburg, N. Y. 



f — Mytiloidea. 

 Leptodesma acutirostrum. 



Page 234. 

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

 Chemung group. Warreti, Pa. 



Leptodesma mytiliporme. 



Page 23.'). 

 See Plate 25. 

 Pig. 22. The right valve figured on plate 25, fig. 7, redrawn to correct the outline and the form of the body. 

 Fig. 23. A small left valve. 



Fig. 24. A view of left valve given in correction of lig. 11, plate 25. 

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

 Chemung group. Road from Olean to Smethport, Pa. 



