390 On Lingulasma^ Etc. — Uirich. 
rather strongly convex, the brachial more than the other, and 
both with the point of greatest convexity a little behind the 
middle. The central space on each valve contained within 
two lines drawn from the beaks to the anterior angles, is 
flattened. Midway between these lines there is a more or less 
faintly elevated broad fold which produces the slight central 
protrusion of the anterior margin already noticed. The lateral 
slopes are also flattened and, on each side of the umbones, 
even somewhat concave. Surface with fine but rather irregu- 
lar concentric lines, just visible to the naked eye, and, at var- 
iable intervals, with stronger undulations. The concentric 
lines bear hollow granule-like elevations arranged so as to 
form series radiating from the beaks. On the lateral slopes 
these " granulations " are elongated and impart a frequently 
interrupted or imbricating appearance to the concentric lines 
(fig. 5 d, upper half). On the anterior slope this appearance 
is not apparent. Here they look more like the broken bases 
of short tubular spines. Here, also, the radial series formed 
by them are separated by wider interspaces, there being only 
about eight in 5 mm. at the front margin to eleven or twelve 
in the same space at the posterior angles. Casts of the in- 
terior exhibit concentric furrows near the margins and obscure 
radial lines over the anterior half. 
Length of best specimen, 40 mm. ; width, 27 mm. ; depth of 
both valves, 19 mm. ; depth of brachial valve, 10.5 mm. Some 
specimens appear to have been comparatively shorter, but, as 
they have clearly suffered through compression, we may reas- 
onably doubt that they were so originally. 
This species must be closely related to Lingula canadensis 
Billings, from a similar position at the Island of Anticosti. 
Also to Z. tenuigramilata McCoy, and L granulata Phillips, 
described from Lower Silurian deposits of England. The last 
is a smaller shell, and the others are proportionally shorter 
and wider anteriorly. All have fine surface markings. 
It aff'ords me much pleasure to connect the name of Mr. 
Charles Schuchert, now of Albany, N. Y., with this highly in- 
teresting species. This gentleman has selected the brachio- 
poda as a specialty and owns one of the finest collections of 
American paleozoic forms of that class known to me. It is to 
be hoped that he will make good use of this advantage and 
that we may soon be favored with some of the results of his 
