PLATE I— Continued. 



LINGULA, BEUGuii;RE. 



Page 2. 

 LiNGULA PUNCTATA, Hall. 



Fig. 26. An enlargement of the external sui-face; showing- the character of the ornamentation. X 12. 

 Fig. 27. A cast of the interior of the brachial valve; showing the indistinct lateral scare, the vascular 



sinuses and their ramifications. X 2. 

 Fig. 28. An internal oast of a pedicle-valve ; shovving,the comjiound latei'al scars and the bi-oad centrals. 



X 2. 



Hamilton shales. Canandaigua Lake, N. Y. 



LiNGULA Delia, Hull. 



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

 a very strong median septum. X 2. 



Hamilton sViales. Canandaigua Lake, N. Y. 



Llngula scutella, sp. uov. 



Fig. 30. An internal east, indicating that the muscular region of the valve was depressed, instead of thii'.k- 

 ened and elevated as usual. X 2. 



Chemung ^roup. Alleghany comity, N. Y. 



LiNGULA WhITII, Wtlicott. 



Fig. 31. A copy of Mr. Walcott's figure of the brachial valve of this species (Palaeont. Eureka District, pi. 

 xiii, fig. 3). X 2. ■ ' ' ' 



Lower Devonian. Atrypa Peak, Eureka District, Nevada. 



LiNGULA Melie, Hall. 



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

 Wavei'ly group. Berea, Ohio. 



LiNGULA (GlOSSINa) FLABELLULA, .Sp. IIOV. 



Fig. 33. A very large example, from which a portion of the shell has been exfoliated, without sliowing 

 any traces of muscular markings. The anterior margin is i-epresented with too great a 

 curvature. JSTatural size. 



Waverly grouji. Seiotoville, Ohio. 

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

 Berea grit. Bei-ea, Ohio. 



LINGULEPIS, Hall. 



Page 59. 

 LiNGULEPIS PINNIFOKMIS, Oweil. 



Fig. 35. An internal cast of a pedicle-valve ; showing the faint median septum, and the elongate muscular 



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

 Fig. 36. An internal cast of the brachial valve, in wliich the muscular impression is flabellate, the central 



and lateral scai'S being quite distinct, the latter somewhat bilobed. X 2. 

 Potsdam sandstone. Falls of the St. Croix, Minnesota. 



