OF NORTH AMERICA. 
51 
Observations. — This species, related to the Ter. reniformis Sow. (See: Mineral Conchology of Great 
Britain, plate 496, fig. 1, 2, 3, 4.), differs from it in not being transverse, and also because the sides 
of the beaked valve are not inflated so as to hang below the edges. The Bhynchonella Missouriana Shu- 
mard (See: First and Second Reports of the Geological Survey of Missouri, by Swallow; Part //; Paleonto- 
logy, p. 204; pi. C, fig. 5 a, 5 b, 5 c. Jefferson city, 1855.) also resoinbles very much the Ter. Rocky- 
mmtana-, but it is more gibbous and its sinus is larger. 
Locality. — I met with but two imperfect specimens that appear to have been laterally com- 
pressed. Pecos village, New Mexico, where it is found in company with the Prod, semi-reticulatus 
and the Ter. subtilita. 
Explanation of figures. — Plate VI, fig. 13, 13 a. Imperfect specimen. 
» VI, fig. 13 b. 13 c. Another specimen laterally compressed. 
TEREliRATULA MORMONII n. sp. 
Plate VI , fig. 11 , Ha, lib, lie. 
Description. — Longitudinally orbicular; lateral and front margin in one plane, without trace of medial sinus; 
valves equally convex. Beak small, prominent; ridges equal, simple, rounded, radiating; intervening sulci deep 
and angular. 
Observations. — This species resembles much the Ter. radialis Phillips (See: Geology of Yorkshire, 
Part 11, the .Mountain Limestone district, p. 223; pi. XII, fig. 40, 41. London, 1836.), differing only 
by its more elongated form and more prominent beak. 
Locality. — This line fossil was found in the Mountain Limestone of the vicinity of the capital 
town of the Mormons, Great Salt Lake city. 
Explanation of figures. — Plate VI , fig. 11 , 11 a , 11 b, 11 c. Different views of the same specimen. 
TEREBRATULA UTA n. sp. 
Plate VI, fig. 12, 12a, i2b, 12c. 
Description. — Shell inoquivalved , as wide as long, more or less irregularly triangular. Beak small, acute, not 
much recurved. The sinus of the large valve is w ide . about half the total breadth, the .surface of the two valves are de- 
corated each with nine ribs, sharp near the margin, and beginning at a certain distance from the beak; the mesial 
fold has three ribs. 
Observations. - This species is unlike any hitherto found in the Carboniferous rocks, and resembles 
in its form the Terebralulw rimosa, furcillata and especially cynocephala of the Lias and Lower Oolite of 
Europe. Davidson figures a variety of the Rhynchonella cynocephala with three plaits on the mesial fold 
(See: A Monograph of British Oolitic and Liassic Brachiopoda, by Thomas Davidson; pi. XIV, fig. 12, 
12 a, 12 b; p. 77. Loudon, 1852. — Paleontographical Society — ) that is very similar- to the Ter. Ula: 
but the fossil of Davidson is larger, wider, and less triangular. 
Locality. — This species was found in company with the Ter. Mormonii, Royssii, subtilita, and 
with the Prod, semi-reticulatus, near the Great Salt Lake city in Utah Territory. 
Explanation of figures. — Plale VI , fig. 12 . 12 a, 12 b , 12 c. Dill'erent views of specimen , natural size ; fig. 12 c 
is badly printed, and not much like the original. 
TEREBRATULA ROYSSII Leveillc. 
Plate VI , fig. 10 , 10 a , 10 b. 
Description. — Transversely oval , moderately gibbous ; lateral and front margins nearly in one plane , till after 
half an inch in length , when a semi-elliptical sinus becomes developed in the front margin , with a corresponding 
