368 PALAEONTOLOGY OF NEW YORK. 



Pabastrophia latiplicata, sp. nov. 



PLATE l.XIII FIGS. 23-27. 



This species is distinguished from the two preceding by its smaller size, less 

 robust form, two broad plications on the fold and one in the sinus, with but a 

 single pair on the lateral slopes. 



Niagara dolomites. Near Milwaukee, Wisconsin. 



LiORHYNCHUS Lesleyi, sp. nov. 



PLATE LIX, FIGS. 34-36. 



Shell of medium size with shallow pedicle-, and deep brachial valve. Median 

 sinus on tlie former well defined ; median fold on the latter broad and not 

 sharply delimited. Surface of both valves sharply and abundantly plicated. 



Upper Devonian. Pennsylvania. 



Barrandella Areyi, sp. nov. 



PLATE LXXI, FIGS. 14-16. 



Shell small, ventricose, with sinus on the pedicle-valve and fold on the bra- 

 chial valve. Surface on both valves rather sharply and coarsely plicated, the 

 largest plication being in the median sinus, with traces of finer ones on the 

 slopes of the sinus. The median fold bears two well-defined plications with 

 faint traces of others, while on each lateral slope of the valves there are four or 

 five less sharply angular ribs. 



Clinton group. Rochester, N. Y. 



CONCHIDIDM GreENII, sp. nOV. 

 PLATE LXVI, FIGS. 20-22. 



Shell subequally biconvex, ventricose, subcircular in marginal outline. Um- 

 bones full and rounded, both incurved, that of the pedicle-valve somewhat 

 elevated. There is no evidence of median fold and sinus. Surface of each 

 valve bearing, over the pallial region, from forty-five to fifty rounded plications, 



