PLATE XXII— Conlinueil. 



LErrODESMA USIBOXATUM, VftT. DEPKESSUM. 



]'a;.'0 19'J. 

 Sof Plate 90. 

 Fi?. 14. The spnoiimMi il.'.scril.eil. Another tifjure of tlxii? speq^IU«^l jsigiveu on plate 90, fife'. Id. 

 Chemung' ^rouji. ^TopDli, Caltaraayus Co., N. T- 



Lepto: - aviforme. 



See Phite 23. 



Fig. 15. The left Viilve cUwci-ibed. The antevior end shonM 1"- '■•' -.•.;<.■. 1 :.-i m,.,-.- ovi.Mi.le,! .•m„1 .n-ni,-. 



and the exireniity <■<( tlie wing a.s nuicronate. 

 Chemung group. Near Ithaca, N. T. 



LePTOOESMA POTENS, V;U. .ILVKNr.. 

 Page MO. r 



Kl^'. li;. A l.-li i.-ih.-. 



Chemung group. Bust llaiulolph. ' F. 



Licioi'TKuiA Ciie.muxgexsi.s. 



I'ajfC 17-2: >  I i.i 

 Figs. 17, IS. Opposite views of the original .speeimcn showing Ihe left and right valves. The right valve i.s 

 imlieildeil vertically in the roek and has beeanmeh shortened by the shrinkage or compi'ession 

 of the layers, while the surface of the shell has been slightly, wn-inkled from the ^arae cau.se. 

 Cliemung group. Eiyht inihs north of Bhmiiamti';:. .T. 1'. 



Lei'touesma Ly.saxuer. 



tase 21fi. 

 See Plate 90. 

 Fi". 22. A left valve. The figure is partially lestored and should rejiresent the.body as considerably wider. 

 Chennuig group. Maiinfidd. Tiorja. Co., I'u. 



Leptojjesma extexuatu.m. 



Page -207. 

 See Plate 90. 

 Fig. 23. An imperfect left valve. Another figure of this specimen is given on plate 90, fig. 17. 

 Chemung group. PJni'qislMrr/, AUeffJiaiiy Co., iV. I'. 



Pteuoxites kostuatus. 



Page 2»S. 

 Fig. 24. The left valve described. 



Chemung gi-ouji. JiockvUle, N. Y. 



PtEHOXITES PaOFl'XDUS. 



l'age-237. 

 Fig 2.1. A small left valve. 



Chemung group. A'cic Albion, C'attaruiiyii.i (.'<>., ^V. X'. 

 Fig. 2(5. A larger example. The anterior side should show reguLir concentric uudnhitions. 



Chennuig group. Jiandntpli. Catlaraiif/us Co., N. )'. 

 Fig. 27. A large indiviilual, imperfect on the anterior end. 



Chemung group. Niar Oleaii, N. T. 



Leptoijessia aliforme. 



Pago 2-20. 

 See Plate 91. 

 Fig. 28. A right valve. This speiimen is redrawn o.i plate 91, tig. 2, ami represents more rlearly the 

 specific ehnracters. I  



Chemung group. Niiir Aiif/fJli-ii. Allic/haiiy Co., N. Y. 



