208 



Found ill the Moscow shales, at Sections 2, 8, 4 (rare) ; 

 Encrinal limestone, at Section 5 (rare) ; Hamilton shales, at 

 Sections 5 to <S, and on the Lake Shore (eA'erywhere abun- 

 dant); Strophalosia bed and Transition shales, on the Lake 

 Shore (not nncomnion ) ; Marcehus shales, on the Lake Shore 

 (rare). 



Measurements. — A very much extended individual gave: 

 width, 100 mm.; height, 15 mm.; average width is less. 



Spirifek tullius. Hall. (Fig. 115. ) (Pal. N. Y., Vol. 

 IV., p. 218. PI. XXXV.) 



Distinguishing Cliaracters. — Small size (es])ecially so in 

 this region); gibbous character ; sub-elliptical outline; well- 

 defined sinus, which extends quite u]:) to the beak; strongly 



i^p^c ^'sm 



Fig. 115. Sjiirifer tullius. Ventral and cardinal views of pedicle valve and brachial 

 valve of the normal form, as it occurs in the center of the State ; the Eighteen Mile Creek 

 specimens are much smaller (from Hall). 



marked fold, which is wide at the bottom and naiTow at 

 top; comparatively high cardinal area of pedicle valve; low, 

 round and rather flattened surface plications; and fine, 

 uniform radiating stria', which are esjiecially well visible be- 

 tween the plications, on the fold and in the sinus; faint 

 concentric stria^ also occur. 



Found in the Styliolina band, at Section 1 ; upper Moscow 

 shales, between one and one-half and three feet below the 

 Styliolina limestone, at Sections 2, 8, -1 (common). 



Measurements. — .\verage specimen in this region: width, 

 8 mm.; height, 5 mm. 



Spikifer (Delthyris) sculftilis. (Hall.) (Fig. IIG.) 

 (Pal. N. Y., Vol. IV., p. 221, PI. XXXV.) 



Distinguisliing Cliaracters. — Medium size; gibbous char- 

 acter; semi-elli})tical to sub-triangular outline; extended 

 hinge line; sub-angular sinus, and strongly elevated fold. 



