PLATE I— Continued. 



LINGULA, Bruqui^re. 



Page 2. 

 LiNGULA PUNCTATA, Hall. 



Kig-. 26. An onlai-^ement of the external surface; showing the character of the ornamentation. X 12. 

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



sinuses and their ramifications. X 2. 

 Kig. 2S. An internal Ciist of a pedicle-valve ; showing' the compound lateral scars and the bi-oad centi-als 



X 2. 



Hamilton shales. Canandaigua Laki, N. Y. 



LiNGULA Delia, Hall. 



Fig. 29. The type-specimen, a brachial valve (?), retaining most of the surface ornamentation, and showing 

 a very strong median septum. X 2. 



Hamilton shales. Canandaigua Lake, N. T. 



Ll\gula SCUTELLA, sp. UOV. 



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, N. Y. 



LiNGULA WhITII, Wlllcott. 



Fig. 31. A cojn' of Mr. Walcott's figure of the bi-achial valve of this species (Palseont. Eureka District, pi. 

 xUi", fig. 3). X 2. 



Lower Devonian. Atrypa Peak, Eureka District, Nevada. 



LiNGULA Melie, Hall. 



Fig. 32. A valve, showing the bi-oad, low median septum, with its elevated margins. X 2. 

 Waverly group. Berea, Ohio. 



LiNGULA (GlOSSINA) FLABELLULA, Sp. IIOV. 



Fig. 33. A very lai-ge example, from 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 

 curvatiu'e. Natural size. 



"Waverly group. Seiotomlle, Ohio. 

 Fig. 34. A smaller valve, exposing the inner laminse of the shell, with faint radiating lines. Natui-jil size. 

 Berea grit. Bei-ea, Ohio. 



LINGULEPIS, Hall. 



Page 59. 

 LiNGULEPIS PINNIFORMIS, OvVeil. 



Fig. 35. An internal ca.st of a jiedicle-vidve : sliowing the faint median septum, and the elongate musculai- 



.scar, with its lateral and central divisions. X 2. , 

 Fig. 3t). An internal cast of the brachial valve, in which the muscular impression is fiabellate, the centi-al 



and latei'al scars being ipiite distinct, the latter somewhat bilobed. X 2. 

 Potslara sandstone. I''alls of the iStt. Croix, Minnesota. 



