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TRIGONIA striata. 
TAB. CCXXXVIL —Figs, l, 2, and 3. 
Syn. Tricon ia striata. Miller’s MSS . 
Spec. Char. Obtusely triangular, convex, with 
arched, oblique, crenulated costae upon the 
middle and posterior side * anterior side nearly 
covered by numerous elevated sharp ridges. 
Length and breadth nearly equal; the anterior side is di- 
vided into a smooth and a striated part ; the smooth part 
is small, and forms a kind of lanceolate lunette near the 
hinge; the striated part is nearly flat : in some specimens 
it is again divided by an intersection of the ridges. 
Found in the inferior Oolite at Dundry, by Mr. J. S. 
Miller, in whose collection the specimens are deposited, 
with the name above quoted. Figs. 1 and 2 are different 
views of the same specimen. 
TRIGONIA duplicata. 
TAB. CCXXXVII. — Figs. 4 and 5/ 
Spec. Char. Transversely oblong; anterior side 
marked with small undulating ridges, and 
bounded by a strong tuberculated ridge ; over 
the middle are longitudinal crenulated costse, 
suddenly reflected over the posterior side ; on 
the front are short intermediate ridges. 
A. slightly depressed shell; it is wider than long ; the 
posterior side is small; the principal costae are nearly 
straight, and sometimes branched towards the front; but 
generally they are only thinner, and alternate with other 
