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BULLETIN OF THE LABORATORIES 
It may be noted, however, in this connection that it is associated with 
a number of small fossils, which apparently are depauperate forms of 
other, well-known species. 
Locality and position. Beavertown marl, Huffman’s Quarry. 
Clinton Group. 
LAMELLIBRANCHIATA. 
Genus PTERINEA, Goldfuss. 
Pterinea brisa. Hall. 
(Plate VIII, Fig. 30.) 
Since [the description of the specimens from the Soldiers’ 
Home Quarries, a large number of quite perfect specimens have been 
obtained from Brown’s Quarry, near New Carlisle. A very fine speci- 
men, belonging to the cabinet of Prof. W. S. Hoskinson, is here fig- 
ured. 
They are all left valves. The body of the shell is obliquely sub-ovate, 
extremely inequilateral; the anterior wing is rather long, and distinct- 
ly sinuate at its junction with the body of the shell; the posterior wing 
is acute and extends almost if not quite as far as the posterior extrem- 
ity of the shell. The umbo is prominent, rising above the hinge-line. 
The anterior wing is depressed antero-laterally along the hinge-line, 
giving sometimes the deceptive appearance of a hinge-line strongly 
bent at the beaks (as in figure 9, plate 28, Geol. Surv. Ind., Eleventh 
Report). The surface is marked by numerous distinct radiating and 
concentric striae. 
Our specimens compare very well, as near as we can judge, with 
the type figured from Bridgeport, Illinois. The Indiana specimens re- 
ferred to this species have a comparatively greater width, measuring 
vertically from the hinge-line; the concentric striae are usually in the 
form of prominent lamellae, recurving at their edges, often fimbriated, 
characters which our specimens never present. 
Length of one of the largest specimens, measured from the umbo 
to the posterior extremity of the hinge-line, 1 8 mm, to the posterior ex- 
tremity of the body, 21 mm; width measured from the hinge-line ver- 
tically, 14.5 mm. 
Locality and position. Brown’s Quarry, Soldiers’ Home Quarries. 
Clinton Group. 
