1884.] NATURAL SCIENCES OP PHILADELPHIA. 149 



one-fourth inch in the larger specimens ; they rise bj^ an even 

 curve from the rounded, contracted, inter-annular spaces and 

 form sharp angular annulations. 



Longitudinal striations prominent, closely arranged, and are 

 strongest at the bottom of the trough-like depressions, having 

 there the appearance of being minute plications produced by the 

 contraction ; they grow fainter at the apex of the annulations, 

 but continue over them to the next. The sloping sides of the 

 annulations sometimes bear one or two inconspicuous annulations 

 which do not interfere with the contour of the shell. 



The prominence and regularity of the annulations in the older 

 portions of the shell will serve to distinguish it from G. proprius, 

 with which it is associated, and to which it sometimes bears a 

 superficial resemblance in the younger attached part. 



From the Niagara shale at Lockport. 



Cornulites nodosus (n. sp.). PI. Ill, fig. 7. 



Shell small, elongate, tapering graduallj^ to an attenuate, very 

 sharp apex. 



Growing on small foreign bodies ; attached throughout. Sur- 

 face smooth, ornamented by numerous closely arranged nodes, 

 which increase in size as the shell enlarges, and are placed in 

 regular rows across it ; the terminal ones being somewhat elon- 

 gate and attached to the surface upon which it grows. 



The largest specimen found measures five thirty-seconds of an 

 inch in length. 



From the Niagara shale at Lockport. 



Lingula bicariaata (n. sp.) PI. Ill, fig. 8. 



Shell small, ovoid in outline ; beak very acute ; transverse 

 diameter widest half way from the beak ; valves evenly rounding, 

 convex ; with two hardly perceptible parallel median ridges com- 

 mencing at the beak and extending to the outer margin, widening 

 regularly as the shell increases in size. 



Concentric striae fine, even, increasing regularly by several 

 bifurcations. 



From the Niagara Shale at Lockport. 



The specimens described were all collected by myself, and the 

 types are in my collection. 



