Meris. 



394 



\HD IS6I 



15th An. Rt. 1862, pi. 3, f. 17, 18, 19. showing gradations in 

 size and front extension; 10, profile of 19 ; 21, 22, dorsal and 

 profile views of large specimen, probably of this species ; the 

 prolongation in front being wider and more extended than 

 common. — Schoharie grit^ Up. Held. c& Hamilton^ VII 5, 

 Villa, VIII G. 



Meristella rectirostra, Hall, Trans. Alb. Inst. Vol. 10, 



1879. Figures from 

 Collett's Indiana Re 

 port of 1881, p. 301, 

 plate 27, figs. 10, 11, 

 12, back, front and 

 side of type specimen ; f. 13, back of one more slender ; f. 14, 

 shows size and direction of the spires, or gills. Niagara.^ Vl. 



Meristella rostrata. {Atrypa rostrata.) Hall. Report 

 Y//W c.»/. ^ on the Fourth District of New York, 



1843, page 202, fig. 81, 2, a very neat 

 little shell, marked by a few concen 

 trie lines of growth, and apparently 

 found only in the thin bed of Encri- 

 nal limestone (under the Moscow shale., which is the top sub- 

 division of the New York Hamilton) on Eighteen Mile creek, 

 N. Y.— F7//^.— Also in the Tully limestone, VIII d. 



Pu.rT 



Meristella scitula. 



beak to the lower valve. 



{Atrypa scitula; Atrypa circe.) 

 Hall, Report on the Fourth Dis- 

 trict, JS. Y., 1843, page 171, fig. 

 67, 1, a very scaly shell, with 

 hardly perceptible concentric 

 lines, but a characteristic long 



Williamsville, Erie Co., N. Y. Cor- 



niferous {Upper Helderherg) limestone. VIII a. 



Meristella (?) unisulcata. Hall, {Atrypa unisulcata, 

 Conrad, 1841,) 14th An. Rt. 1861, p. 101; 15th An. Rt. 1862, 

 pi. 2, f. 17, a cardinal view of a well-preserved form, from the 

 Upper Helderberg limestone, in which there is a ridge-like 

 fold on the dorsal valve, parallel with and close to the hinge- 

 line or cardinal margin of the valve. In fig. 18, a specimen 

 from the Hamilton group, this fold is more oblique, rising from 



