112 
PROCEEDINGS OE THE ACADEMY OF 
FAVOSITES, Lanark. 
Favosites ? mancus n. sp. Coral a small hemispherical mass, with an ob¬ 
tuse apex ; principal cell-mouths very small, sub-circular; those occupying 
the interstices smaller and angular ; cell-walls strong, prominently raised 
above the general surface. Cells rapidly enlarging and multiplying by fre¬ 
quent gemmation. -No pores, strise or diaphragms have been discerned. 
Diameter <$*]Jolypary, *68 inch ; largest cell-mouths, *05 inch in diameter. 
This differs from F. divergens , White and Whitfield—the only other species 
.described from rocks of this age—in its extremely diminutive proportions, and 
in the apparent absence of diaphragms. There is perhaps as much reason for 
referring this*species to Conopoterium as to Favosites. 
Collected by A. Winchell, in the Goniatite limestone of Rockford, Indiana. 
Trematopora ? vesiculosa, Win. Specimens undistinguishable from the 
Iowa species, in their existing state of preservation, have been collected by A. 
Winchell, at Alan’s quarry, in Hillsdale, Michigan. 
Lingula Cuyahoga, Hall. Numerous specimens, not distinguishable from 
this species, were obtained by the writer from fragments of a hard, calcareous, 
brecciated rock, quarried from a well on the premises of Judge Alan, at Hills¬ 
dale, Michigan. The geological position is apparently in the lower part of the 
Marshall group. The rock here is the nearest approach in physical charac¬ 
ters that has yet been seen to the Groniatite limestone at Rockford, Indiana. 
Occurs also in the “Fine-grained sandstone beneath the coal at Ward’s 
mine, Wethersfield, Trumbull County, Ohio—conglomerate wanting.” Whit¬ 
tlesey’s collection. 
DISCINA, Davidson. 
Discina Gallaheri, n. sp. 
Shell of medium size, nearly circular. Ventral valve with the apex slightly 
excentric ; foramen lanceolate, reaching from near the apex four-fifths the 
distance to the margin, and acute at both extremities. Surface marked by 
about fifteen rigid, sharp, sub-equidistant striae, which gj*e somewhat more 
approximated toward the apex. The striae are less distinct on the shell than 
upon the cast. 
Dorso-ventral diameter about 1*0 ; transverse diameter about 1*0 ; distance 
from apex to dorsal side, *48 ; length of foramen, *33. 
Found at Hillsdale, Michigan, 'on the premises of Rev. F. A. Gallaher, in a 
small loose fragment having the lithological characters of the lower gray 
portions of the neighboring Marshall sandstone. It occurs also in Col. Whit¬ 
tlesey’s collection from Girard and Wethersfield, in Trumbull County, Ohio. 
I at first referred the specimens to D. Newberryi, Hall, (xvi. Rep. N. Y. 
Regents, p. 30,) but direct comparison with the types of that species shows 
that it differs in having more remote, stronger and more regularly equidistant 
concentric strise. In its striation it resembles D. grandis, Hall, from the Ham¬ 
ilton group, but the form is more circular and the strise are relatively less 
remote. 
Discina capax, White, (1864.) Identified in Whittlesey’s collection, “from 
rocks next below the coal canal level, one mile below Girard,” and also at 
«« Girard, Trumbull County,” Ohio. 
The types of D. Newberryi , Hall, (1864,) do not seem to be distinguishable 
from this species. 
PRODUCTA, Sowerby. 
Producta gracilis, n. sp. Shell small, aperture of the ventral valve form¬ 
ing a little more than a semicircle. Ventral valve moderately inflated for a 
Producta, with flattened, smooth, triangular auriculations; hinge-line equal 
[July, 
