BRACHIOPODA. 353 
LhigulasniiitidtE.l 
rather than separate them under a new name. L. tenuigranuluta McCoy* is another 
closely related species, but it and L. canadensis have three flattened slopes, another 
character not seen in the Minnesota material. 
Formation and locality.— hov/GV portion of the Galena limestone, in the quarries at Mantorville 
and near Hader, Goodhue county, Minnesota. The type specimens are from the Hudson River group of 
Anticosti. 
Collectors.— W. H. Scotteld, E. O. Ulrich and C. Schuchert. 
Mus. Reg. Nos. 7681, "682. 
Family LINGULASMATID^, n. fam. 
Genus LINGULASMA, Ulrich. 
1889. Lingulasma, \5x.R\cn. American Geologist, vol. iii, p. 383. 
1889. Lingulelasma, Miller. North American Geol. and Pal., p. 350. 
1892. Lingulasma, Hall. Palaeontology of New York, vol. viii, pt. i, pp. 24, 46. 
Shell subquadrate, linguliform, inequivalve ; the dorsal valve considerably 
the deeper. Beaks apical, that of the ventral somewhat extended beyond the 
dorsal; cardinal margins gently sloping to the sides. Surface with the concentric 
striae raised at irregular intervals into points, these being arranged in radiating 
lines. 
Interior of the ventral valve with a low concave or concavo-convex platform 
occupying from less to more than one-half the length of the shell; the anterior wall 
may or may not be profoundly excavated. The ventral area has been enclosed more 
or less within the shell, making a distinct sheath or shelf, beneath which is the 
umbonal scar. Platform occupied by the progressive anterior, external and middle 
lateral scars. Transverse scars present underneath the platform at its antero- 
lateral angles. Crescentic scars scarcely defined. 
The dorsal valve deep, with a high platform occupying the posterior third or 
one-half of the valve, centrally produced into a short or very long septum. The 
anterior walls of the platform are more or less excavated, deepest close to the sep- 
tum; marked by vascular sinuses laterally directed. The crescent is more or less 
strongly developed, with its center sharply pointed posteriorly. In front of it is the 
umbonal scar, and in the type species there is anterior to the latter impression a 
short, sharp, median septum. Platform occupied by the lateral, transmedian, central 
and anterior muscular scars. Transverse scars situated at the base of the platform 
at its antero-lateral angles. 
Type : Lingulasma schucheiii Ulrich. 
Lingulasma and Lingulops are the only linguloid genera in which interior plat- 
forms are developed, and in this remind one strongly of the same parts in the 
*Sec Davidson's British Silurian UrachioiKxla, p. ;!T. pi. ii, tigs. 9-U. 
-23 
