HUDSON RIVER BEDS NEAR ALBANY 585 



EXPLANATIONS OF FIGURES 

 Plate 1 



1 A pebble of Trenton limestone with Pterygometopu* 



callicephalus, Am pyx hastatus sp. n. and 

 Climacograptus scharenbergi. x2 

 Lower Trenton conglomerate, Rysedorph hill, Rensselaer co. 

 N. Y. 



Paterula amii Schuchert 



2 A partial cast of a pedicle-valve. x6 



Normans kill shale of Mt Moreno near Hudson N. Y. 



Schizotreta papilliformis sp. n, 



3 A pedicle-valve. x4 



4 Profile of the same. x4 



5 A supposed brachial valve. x6 



Normans kill shale of Mt Moreno near Hudson N. Y. 



Leptobolus walcotti sp. n. 



^6 A small perfect specimen; showing fine concentric striation. 

 Somewhat compressed. x6 



7 An internal cast of a brachial valve; showing pedicle-groovy 



median septum and lateral scars. x4 



8 The interior of a brachial valve, showing median septum and 



lateral scars. x6 



9 A very young specimen, partially exfoliated; showing radiat- 



ing striation of internal surface and pedicle-groove. xlO 



10 A strongly concentrically and radially corrugated specimen; 



the usual mode of preservation. x4 



11 The interior of a similar specimen, showing pedicle-groove. 



x4 i • j 



12 A shell, which instead of becoming corrugated, burst on com- 



pression. x4 

 Normans kill shale of Mt Moreno near Hudson N. Y. 



