382 On Lingulasma^ Etc. — Ulrich. 
tral Ky. The form of that species agrees very nearly with 
L. cohurgensis Billings. The surface characters, however, are 
slightly different and it may be a distinct species. The spe- 
cific name is given in honor of Prof. R. P. Whitfield, the ac- 
complished paleontologist of the American Museum in New 
York city. 
Formation and locality: Lower beds (Utica Slate horizon) 
of the Cincinnati group, a few feet about low water mark in the 
Ohio river at Covington, Ky. The figured specimens are from 
the cabinet of Mr. Charles Schuchert. Others belong to the 
author's collection. 
LINQULA MODESTA, n. sp. 
Fig. 4, 4 a, and 4 b. 
Shell small, subovate, widest in the anterior half, the width 
and length, respectively, in four representative cases, 3.5 to 
5.2, 5.5 to 8, 7 to 10 and 7 to 11, the figures representing the 
dimensions in millimetres. Both valves with exceedingly 
little convexity, appearing in most cases perfectly flat. In- 
terior third or half usually uniformly rounded. Front mar- 
gin occasionally somewhat straightened. Sides gently con- 
vex to near the beak which in none of the numerous speci- 
mens examined seems ever to have formed an acute termina- 
tion. Surface with only very faint concentric undulations ; 
even these are quite obsolete, when the shell is preserved in a 
shaly or impure limestone matrtx. Color white or pearly. 
The unusual flatness and nearly smooth surface of the 
valves are the characters relied upon in distinguishing this 
species. It may be argued that the flatness is due to compres- 
sion, but this is evidently not the case, since numerous ex- 
amples have been collected from limestones containing other 
species of Lingula none of which presented any evidence 
whatever, of having lost any considerable amount of their con- 
vexity through that cause. In its outline the species re- 
sembles several others, notably Z. progne and kingst07iensis 
Billings. Both those species have the front margin less 
rounded, the sides straighter and less converging, and the 
beaks, particularly that of the ventral valve, more pointed. 
The outline of L. ohtusa Hall, though a larger shell, agrees 
very nearly with our species. It is, however, a much more 
convex form and generally wider in front. 
Formation and locality : Specimens of this species are 
