CONCHOLOGICAL WRITINGS. " 69 
with concentric wrinkles, large valve with a depression and sinus. 
Length 4-5, thickness 2-5 of the breadth. From the limestone of 
Lake Erie and Ohio, silicified blackish, about one inch. 
38. STROPHOMENES, Raf. 1820. See tract of October. 1. 
Str. levigata. Very smooth, longer vaive convex, lower valve con- 
cave, corners acute, not avriculate, contour arched and even. Length 
4-5 of the breadth. Kentucky limestone. 2. Str. flexilis: Very 
thin, lower valve hardly concave with minute curved strias, upper 
valve convex with minute flexuose strias, corners acute subauriculate, 
length and breadth equal.. Limestone of Ohio, 1 or 2 inches. 
40. CURVULITES, Raf. 1819. Inequilateral, inequivalve, valves 
elongated, curved or crooked, larger valve broader, the smaller often 
angular. 1. C. striata, Raf. 1818. Cuneate curved, base narrow, 
end broad rounded, striated longitudinally, short alternate strias near 
the end. In the Kentucky limestone, 24 inches. 
41. ZONARITES, Raf. Tribe of Atremosia or imperforated 
Terebratulites. Shell subtransversal equilateral, subinequivalve, 
both valves convex with thick concentric wrinkles, hinge linear, beaks 
very small. 1. Z atrata. Nearly rounded, with large wrinkles and 
furrows between. Length 5-6 of the breadth, thickness nearly half. 
Perfect black shell silicified, nearly one inch, from the Knobhills, 
disc. in 1822. 
42. Zonarytes? Tesselata, Raf. Rounded, tesselated by concen- 
tric and longitudinal wrinkles and furrows. Length 7-8 of the breadth. 
From the Knobhills, one inch broad, has only 1 valve incrusted in 
quartz, and with the hinge too imperfect to refer it decidedly to 
this Genus. 
[Continuation of a Monograph of the Bivalve Shells of the River Ohio, and 
other Rivers of the Western States. By Prof. C. §. Rafinesque. (Pub- 
lished at Brussels, September, 1820.) Containing 46 Species, from No. 76, 
to No. 121. Including an Appendix on some Bivalve Shells of the Rivers 
of Hindostan, with a Supplement on the Fossil Bivalve Shells of the 
Western States, and the Tulosites, a new Genus of Fossils. Philadelphia, 
October, 1831.] 
[i] 
Hardly a dozen species of North American fluviatile bivalve shells, 
had been mentioned by Bose. Lamark, Say, and Lesueur, before 
1820, when I described, in a special and ample Monograph, 75 
“species of them! with 40 varieties, mostly discovered by myself, in 
