PLATE I— Continued. 



LINGULA, BuuGuifeRE. 



Page 2. 

 LiINGULA PUNCTATA, Hilll. . 



Pig. 26. An enlargement of the external surface ; showing the character of the oi-namentatACni. X 12. 

 Fig. 27. A cast of the interior of the bi-achial valve; showing the indistinct lateral scars, the vasculai- 

 sinuses and their ramitications. X 2. 



Fig. 28. An internal cast of a pedicle-valve; showing the compound la,teral scars and the broad centrals. 

 X2. 



Hamilton shales. Cananddigua Laki, N. Y. 



LiNGULA Delia, Hull. 



Fig. 29. The type-specimen, a brachial valve (?), retaining pipat of thje sur£Eu:e orDamentation, and showing 

 a very strong median septum. X 2. 



Hamilton shales. Ca?MndatguaLake,.N.T,.,^^^ 



LiNGOLA SdUTELLA," Spl' llOV. 



Fig. 30. An internal cast, indicating that the muscular region of the valve was depi-essed, instead of thick- 

 ened and elevated as usual. X 2. 



Chemung group. Alleghany county, If. Y. 



LiNGULA Whitii, Walcot,t. 



Pig. 31. A copy of Mr. Walcott's figure of the brachial valve of this species (Pateont. Eureka District, iil. 

 xiii, fig.3). X 2. ,.■.•-'.....-■.. II .- . ! 1*^. ' . . , ,., -.i.il.-^,, / '1 :*1 



Lower Devonian. Atrma Peak, Hwreka District, Nevada. 

 LiNGULA Melie, Hall. 



Fig. 32. A \al\e, showing the broad, low rae<lian septinn, with its elevated margins. X 2. 

 Waverly group. Berea, Ohio. 



LiNGULA (GlOSSINA) FLABELLULA, SJl. IIOV. i.i iui M'j .^i, I 



Fig. 33. A very large example, fi-om which a portion of the shell has been exfoliated, without showing 

 any traces of muscular markings. The anterior margin is represented with too great a 

 curvature. Natural size. ' '  i •• : i 



Waverly gi'oup. SciotoviUe, Ohio. .-i '<ui.\i.\-y.,\ii[ •■i[] \ \,.' ) L'L' .!'_• .>^:i''l 



Pig. 34. A smaller valve, exposing the inner laminip of tlv sIipII. T^-ith faint radiating litieS^-" Natural size. 

 Berea grit. Berea, Ohin. 



LINGULEPIS, Hall., 



Page 59. 

 LiNGULEPiS PINNIFORMIS, OwCIl. 



Fig. 'io. An internal cast of a pedicle-valve ; showing the faint median septum, and the elongate muscular 



scar, with its lateral and central divisiongi |X 2. , 

 Pig. 30. An internal cast of tlie brai;hial valve, in which the muscular impression is flabellate, the central 



and lateral scars being quite distinct, the latter somewhat bilobed. X 2. 

 Potsdam sandstone. Ealls'cif the' St. Croix, Minnesota. 



