PART Wy CHAZYAN AND RELATED BRACHIOPODS—COOPER 197 
ing gently to the anterior margin; anterior third flattened; slopes to lateral mar- 
gins fairly steep in the posterior third but becoming gentle in the anterior third. 
Brachial valve rounder in outline than the pedicle valve. Moderately convex 
in lateral profile; fairly strongly rounded in anterior profile; posterior margin 
obtuse, rounded, having an apical angle of about 110°. Beak blunt, reaching the 
margin; umbo somewhat swollen; valve full for two-thirds the distance from 
beak ; lateral slopes moderately steep. 
Measurements in mm.— 
Length Width Thickness 
Hypotype (pedicle valve 109277a) .......... 21.4 13.9 ? 
x Care eS EOQ277D) sere eee 20.7 14.5 ? 
s (ees PPT OOZ77C) IS AER: 18.1 12.6 1.5 
i Ces Teh woOpar7d) , . 523 0 18.8 14.4 ? 
ff (brachial valve 109277e) ......... 14.8 10.0 2 
¥ ae fm mOGoer Ey aii lees 2) i 16.8 12.1 2.0 
: Girne? Beaty LOOZ 77S eevee is are 17.3 12.0 ? 
Types.—Cotypes: Cornell Univ.; hypotype: Carnegie Mus. 5432; figured 
hypotypes: 109277a,c,f,g; unfigured hypotypes: 109277b,d,e. 
Horizon and locality.—Lower sandstone of the Chazy group in New York: 
At Valcour Island, and Crown Point, Plattsburg (15’) Quadrangle. In Ver- 
mont: On South Hero and Isle La Motte, Rouses Point (15’) Quadrangle. 
Discussion.—This species is characterized by its subpentagonal outline with 
greatest width near the anterior margin and the gently curved anterior margin. 
The latter feature gives the valves an appearance of possessing a truncated an- 
terior, but in fact it is broadly curved. 
An attempt was made to determine internal features by dissolving the shell 
away from its matrix. Although some good impressions of the exterior were 
obtained, the internal features are not sufficiently distinct or well-enough pre- 
served to leave traces on the sandstone. Fine radial lines appear on the inside 
of exfoliated specimens of both valves and the casts of interiors. Such lines are 
common in many linguloid shells and may be the impressions of setae. 
A few immature specimens indicate that L. brainerdi is a somewhat longer 
and more slender shell in its early maturity. The valves at that time are pro- 
portionately longer and the outline more rounded and elliptical. The greatest 
width remains in the anterior third, but it is by no means so pronounced as in 
the older shells. 
Lingulella brainerdi differs from L. huronensis Billings in its proportions, the 
location of the greatest width near the front rather than near the middle, and in 
having the greater height in the posterior third. Pseudolingula lutirellensis 
Cooper, new species, has a pentagonal form similar to that of L. brainerdi but 
is proportionally wider and has a much flatter shell. 
LINGULELLA ? CLOCHENSIS (Foerste) 
Lingula clochensis Forrste, Bull. Sci. Lab., Denison Univ., vol. 17, p. 253, pl. 2, figs. 11a, 11b, 
1914. 
Types.—Holotype: G.S.C. 8403; paratype: G.S.C. 84038. 
Horizon and locality —Lowville”’ formation, La Cloche Peninsula, Ontario. 
