304 



PALJEONTOLOGY OF NEW-YMIK. 



363. 14. MURCHISONIA UNIANGULATA, var. ABBREVIATA. 



Pl. LXXXIII. Figs. 2 a, b, c, d. 

 Compare Murchisonia uniangulata, pag. 179, pi. 3S, fig. 8, of this volume. 



Conical or subfusiform ; volutions about four or five, rapidly diminishing from the apex ; 

 last whorl angular on the middle ; centre of the whorls marked by a double depressed 

 spiral band, separated by a narrow space, which is not marked by the striae ; surface 

 marked by fine striae, which form a deep retral bend on the body of the whorl where they 

 meet the spiral band. 



This species resembles, in form, the M. bicarinata of the Trenton limestone ; but it 

 differs essentially in having the volutions angulated only on the centre. The specimens of 

 this species which occur in the Hudson-river group, are all shorter than the M. uniangulafa 

 of the Trenton limestone. The carinal band in that species is obscure, and I cannot decide 

 whether it be double, as in the specimens under consideration. 



Figs. 2 a, b. Two specimens which preserve a part of the shell. 



Fig. 2 e. A portion of the surface of the last volution magnified, showing the double spiral band. 



Fig. 2 d. A specimen with the volutions more acutely angulated, but apparently identical. 



Position and locality. In the calcareous higher portions of the group at Turin, Lewis 

 county, and in a similar situation near Rome, Oneida county. {State Collection.) 



225. 13. PLEUROTOMARIA SUBCONICA. 



Pl. LXXXIII. Figs. 3 a, b, e, d, e. 

 Reference Plevrotomaria siibconica, pag. 174, pi. 37, figs. 8 a, b, c, d, of this volume. 



This species is not unfrequently found in the shales of the Hudson-river group, but 

 usually in such a condition as not to be readily recognized. All the specimens yet seen are 

 casts, preserving in one or two instances some remains of the vertical striae and the carina, 

 upon the centre of the last volution, It can be recognized by its almost uninterrupted 

 conical form and broad volutions, with a prominent carina on the last one, which is pre- 

 served in the casts, while the higher volutions are obtusely angulated near their base. 



I have received specimens of the same species from the northwestern part of Wisconsin, 

 collected by the late Mr. Nicollet. 



Fig. 3 a. A specimen preserving the vertical strife. 



Fig. 3 A. A portion of the same enlarged. 



Figs. 3 c, d. Imperfect casts, from the shales of the Hudson-river group. 



Fig. 3 e. A more perfect cast of the same species, from Wisconsin. 



Position and locality. Tliis fossil occurs in the central portions of the Hudson-river group 

 at Turin, Pulaski, and otiicr places in tiie State of New- York. The western specimens are 

 in limestone, associated with other fossils known as belonging to the Trenton limestone. 



{State Collection.) 



