344 THE PALEONTOLOGY OF MINNESOTA. 
{Lingula riciniformis, var. galenensis. 
small size; second, a very sharply defined circular stage, which is of a lighter color 
than the shell surrounding it. This second growth has been appropriately called 
the Obolella stage, and around it the shell begins to assume its specific form, growing 
most rapidly in the anterior region, and but comparatively little laterally and pos- 
teriorly. At maturity, the apex is no longer marginal, as in the Obolella stage, but 
has become submarginal through the addition of shell substance posterior to the 
protegulum. These stages of growth indicate that the course of development of 
Lingula is through Paterina—Obolella—Lingula. 
This species can be separated readily from Lingula attenuata Hall (non Sowerby) 
—L. daphne Billings—L. (Glossina) trentonensis Conrad, sp., by its oval form and 
obtuse beaks, The latter is also more attenuated towards the apex, and is now 
referred to the sub-genus (7lossina, Phillips. LL. elongata Hall differs in being twice 
the size of L. riciniformis. 
Formation and locality—Near the base of the Galena shales, associated with Zygospira recurvirostris 
Hall. A single example has been discovered at Minneapolis, while from St. Anthony Hill, a suburb of 
St. Paul, Minnesota, a number of specimens have been procured, Also in the Trenton at Middleville, 
New York, and Charlesbourg, Canada. 
Collector.—C. L. Herrick. 
Mus. Reg. No. 785. 
LINGULA RICINIFORMIS, Var. GALENENSIS W. and S. 
PLATE XXIX, FIGS. 10 and 11. 
1892, Aprill. Lingula riciniformis, var. galenensis W. and S. American Geologist, vol. ix, p 284. 
The conspicuous differences between L. riciniformis Hall and this variety are 
that the former is constantly two-thirds the size of the latter, and that the greatest 
width is across the center of the length of the valves, while the variety is widest 
in the anterior third. In the Galena horizon at Oshkosh, Wisconsin, this variety is 
not rare, and attains twice the size of L. riciniformis Hall. 
Formation and locality—From the Galena shales of the north branch of the Zumbro river, at the 
upper bridge, near Kenyon, and near Fountain, Minnesota. Also from the Galena horizon at Neenah and 
Oshkosh, Wisconsin. 
Collectors.—W. H. Scofield and Charles Schuchert. 
Mus. Reg. Nos. 7672, 7673. 
Lineuta moprEsta Ulrich. 
PLATE XXIX, FIG. 41. 
1889. Lingula modesta ULRicH. American Geologist, vol. iii, p. 382, figs. 4-40. 
Original description: “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 millimeters, Both valves 
