HUDSON RIVER BEDS NEAR ALBANY 571 



the center, not procumbent in any direction; pedicle-groove begins 

 on top of beak, is deepest directly behind the beak and becomes 

 shallower toward the margin, to which it extends. Surface cov- 

 ered by very fine, regular, concentric growth lines which are not 

 interrupted by the pedicle-groove. Shell apparently quite thick; 

 not so much flattened as those of other forms. 



A low convex shell with two posteriorly diverging oval mus- 

 cular scars may represent the corresponding brachial valve. 



Dimensions. Length of type specimen, 3 mm, width 3.2 mm. 



This form differs from Sch. ovalis, Hall and Clarke, of 

 the Trenton, by its subcircular outline and more central position 

 of the beak; from Sch. conica, D wight, also from the Tren- 

 ton, by its smaller convexity and equal slope. It has the circular 

 outline and regular concentric striation in common with Sch. 

 p e 1 o p e a , Billings sp., from the Canadian Trenton and Oalena 

 shales and Salmon river (Hudson river) formation of Minnesota 

 (49: 365), and with the interesting Sch. minutula, Schuch- 

 ert and Winchell (p. 366). The latter occurs in abundance asso- 

 ciated with stems of Diplograptus in the " lower portion 

 of the Hudson river group near Granger Minnesota ^^ (=Utica 

 shale). Sch. papilliformis differs from both these species 

 in size, the more central position and more abrupt elevation of 

 the beak or apex, and in the presence of a distinct pedicle-groove 

 instead of the apical circular pedicle opening of the others. 



It will be seen that these minute brachiopods do not directly 

 determine the position of the Normans kill graptolite shales, as 

 all three species are peculiar to this horizon, but their relation- 

 ship to Trenton and XJtica forms of the genera Leptobolus 

 and Schizotreta, would certainly suggest the Trenton- 

 Utica age of the shales in question. 



It is certainly peculiar that only these minute, thin-shelled, 

 non-calcareous brachiopod valves and no other fossils occur asso- 

 ciated with the graptolites. Their size, thinness and the com- 

 position of their shells indicate strongly that they led a pseudo- 

 planktonic life. Winchell and Schuchert suggest that Sch. 



