Professor Emerson on JfaWs Geolorjieal Collections. .570 



Endoceras proteiforme, Hall. 



1843. Endoceras proiciformc, Hall. Pal. N. Y., vol. i, p. 208, pi. xlv-1. 

 1843. ? p. 311, pi. Ixxxv, fig. 1. 



Ten or more specimens of this form are present, which are all flattened, and 

 resemble closely the flattened forms from Fort Plain, X. Y., from the IJtica slate, 

 referred by Hall with doubt to this species. Five of the specimens are flattened, 

 showing neither septa nor distinct surface markings, but tapering at exactly the 

 same angle as the Fort Plain specimens. Four retain very distinctlj' the exterior 

 marking, and agree so exactly with the fig. 3, pi. lix, loc. cit, of the surface mark- 

 ing of E. proteiforme^ var. lineolatum, that it might have been the original from 

 which the drawing was made. The surface is covered with transverse stria; 3 to 

 the mm. Two other specimens show the points of small shells, flattened, sei)ta 

 distant not quite ^ of the diameter. The specimens were found one in a gray 

 li?uestone associated with crinoid stems, the others in the black shaly limestone 

 \vith Triarthrus Beckii, Calymene senaria, Lingula curta, Diplograptus dentatus, 

 &c. 

 Orthoceras laqueatum. Hall. "? 



Orthoceras laqueatum, Hall. Pal. N. Y., i, p. 206, pi. Ivi, fig. 2 a-c. 

 A single impression agrees in the character of the stria tion with this 

 species. In black shaly limestone. 



Tentaculites. ? 



Length of largest piece, 1.1 mm. ; width, .1-.2 mm. Large masses of tUe 



buff limestone, No. 112, are filled with minute tubular ^ ^_ 



tapering cavities, showing traces of delicate transverse #' ,,, 



striation, now covered with scattered elevations, due to ^— .^^v- 



subsequent crystallization apparently of hematite. These ^. .^ -, , 



Fig. 4 magiiined tweiity- 

 may be cast of a minute shell or of the siculae of grap- seven times. 



tohtes from which the chitine has been wholly removed. They are so numerous, 



however, and the limestone is so compact and free from carbonaceous matter, that 



it does not seem possible that they can have been chitinous. Their organic origin 



is not entirely certain. 



Leperditia alta. Con. sp. 



1856. Leperditia alta, Jones. Ann. and Mag. Nat. Hist. 2cl ser. xvii, p. 89, pl. vii, lig. 6, 7. 

 Length, left valve, 4 mm. ; breadth, 2,% mm. Carapace valve strongly con- 

 vex, minutely papillose under strong lens, pale chestnut brown, slightly oblong. 

 Hinge-line straight, angles at end of hinge-line not strongly marked, anterior 

 end slightly narrower than posterior, anterior tubercle indistinct, central tubercle 

 not seen. 



