On Lingulasma, Etc. — Ulrich. 383 
abundant in the hydraulic limestones near the middle of the 
Trenton group, at Frankfort, and other localities in central 
Ky. The strata which hold them are locally known as the 
" Modiolopsis bed " from the large number of shells of a new 
species of that genus (provisionally named M. oviformis) 
contained in them. These beds have yielded fine examples 
of Trematis ottawaensis Billings, and a number of species of 
Lingula. L. modesta is next met with in the transition beds 
of bluish crystalline limestone near Paris, Ky. The " river 
quarry " beds about Cincinnati also contain it, but individuals 
are not of common occurrence. I have also met with ex- 
amples in the blue shales near the tops of the Cincinnati 
hills. 
lilNGUIiASMA, n. een. 
Shell oblong, subquadrate or sub-pentagonal ; substance of 
valves moderately thin, apparently of the same composition 
as in Lingula. 
Pedicle valve with a slightly projecting obtusely pointed 
beak ; under it a large faintly arched deltidium, most of which 
seems to have been internal {i.e. extended within the poster- 
ior margin of the brachial valve.) Area apparently absent. 
A small socket on each side of the posterior ends of the con- 
verging deltidial borders, and, just opposite their anterior ends 
(on each side) a rather large sub-triangular scar. A large 
triangular platform extend:* from the base of the deltidium to 
about the middle of the valve. The platform is elevated, tri- 
lobed, with its antero-lateral extremities recurved, and the an- 
terior end bisinuate, the central portion being a little prom- 
inent and, below, produced into a low median ridge. On the 
inner slopes of the anterior halves of the lateral lobes two 
large muscle-scars, apparently the lateral pair, are faintly 
traceable. The median and anterior pairs were probably at- 
tached to the anterior half of the central lobe. 
Brachial valve with the posterior end narrowly rounded ; 
beak very small. On the inner side, just within the narrow 
flattened posterior border, there is a small transverse ridge 
(a) sinuate centrally on its anterior side and slightly thick- 
ened at the ends. This ridge forms the truncate apex of the 
arch-like border of the platform and its swollen ends may 
have fit into the small sockets situated just within the apex of 
the opposite valve. The platform is concave both transverse- 
