BRACHIOPODA. 343 
Lingula riciniformis.] 
The figure of this species, as given by Billings, shows a strong median sinus, 
which does not reach the anterior margin, but in the description, it is said that the 
“shallow sinus extends all along the median line from near the apex to the front 
margin,” and that the latter is “straight or slightly sinuate” in the middle. Since 
the example before us agrees with the original description, we do not hesitate 
to identify this species as occurring in the Northwest. This example and the 
one figured by professor Hall, like the Canadian specimens, are broken along the 
cardinal line, and must have been “obtusely angular,” as the earlier lines of growth. 
are semicircular in outline, or Paterina-shaped, and not much crowded laterally. 
The shell substance is thick, and composed of many corneous and calcareous layers, 
with the surface glossy. 
Formation and locality.—F rom the lower portion of the Hudson River group, or Loraine shales, ina 
small quarry on the north side of the Upper Iowa river, about two miles west of Granger, Minnesota. 
Mr. E. O. Ulrich reports the species from the same horizon near Wykoff. The original specimens were 
found in the Trenton limestone, at Montmorenci falls, and Island of Montreal, Canada. 
Collector.—The specimen here figured was found by Mr. R. H. Hasse, and kindly donated by him to 
the survey collection, 
Mus. Reg. No. 7671. 
Lineuta RicintrorMis Hall. 
PLATE XXIX, FIG. 9. 
1847. Lingula riciniformis HALL. Paleontology of New York, vol. i, p. 95, pl. XxX, figs. 2a, 2b, 2c. 
1892. Lingula (Glossina) riciniformis HALL. Ibidem, vol. viii, pt. i, pl. I, fig. 3. 
Original description — Oval, convex, slightly attenuated towards the beak, which 
is obtuse; surface nearly smooth, or with fine nearly obsolete concentric lines. 
Fine radiating strive are sometimes visible; and the surface is sometimes slightly 
ridged, as if from elevated lines beneath the outer lamina of the shell.” 
Fie. 24. Stages of Lingula riciniformis. p. protegulum; o. obolella; s, nealogic. 
Our specimens of this species show three distinct stages of development; the 
first shelled condition, or “protegulum,”* which is not distinct, owing to its very 
*For a definition of this term, and description of the earlier stages of growth in Brachiopoda and their importance 
in classification, see Dr. C. E. Beecher’s valuable papers on “ Development of the Brachiopoda,” American Journal of 
Science, April, 1892. 
