2 i6 The American Geologist. October, 1903.. 
It is to be noted as pointed out by Meek (Geol. Sur. Ohio, Pal., 
Vol. I. 1873, P- 8l )> that Hall's figures (Nat. Hist. New York, 
Pal., Vol. I, pi. 31 B, figs. 4a, 4b) of Leptaena planumbona are 
inaccurate in representing strong concentric transverse folds 
or wrinkles. It is a little singular that de Blainville's figures 
if they really represent the same shell, should have the same 
defect. The Strophomcna planumbona in its typical, common 
form has a smooth surface with the growth lines rarely con- 
spicuous. 
In 1852 Davidson ( Monograph of the British Fossil Brach- 
iopoda, Part I, p. 105) carefully defined the "Genus Stroph- 
omcna (Rafinesque) Blainville, 1825," gave as the "Type — 5". 
rugosa Raf. ?=S. planumbona or 6". altcrnata/' with the re- 
mark that "no one seems to have clearly pointed out or identi- 
fied with certainty 5\ rugosa of Raf." 
In a tract published at Philadelphia in Oct., 1831, Rafin- 
esque defined his genus thus: "Strophomenes, Raf. Equilateral, 
hinge broad, great valve notched by a lunulate sinus receiving 
a lunulate projection from the smaller valve." Xo species is 
mentioned. In November of the same year he defined two spec- 
ies Str. laevigata and Str. Hcxilis. Neither can be recognized 
from his short descriptions. 
Beginning with Conrad and Emmons, 1839-1842, the name 
Strophomcna has been widely used in American paleontological 
literature in a broad sense, a common Ordovician form, (now 
the Rafincsquina altcrnata of Hall and Clarke, 1892), with its 
innumerable varieties, gradually coming to typify the genus. 
There is nothing about the Strophomcna planumbona 
{ Hall ) to suggest the descriptive term rugosa. It does seem 
probable, indeed almost certain, that Rafinesque applied the 
term to the shell now commonly known as Leptaena rhomboid- 
alis, (see Hall. Xat. Hist. New York, Pal., Ill, p. 195 ; Meek, 
Geol. Sur. Ohio. Pal., I, p. 73 ; S. A. Miller. The Natural Sci- 
ence Jour., I, pp. 30. t,t,). By the time it came into de Blain- 
ville's hands, in some way a transfer of name had taken place 
(due to mixing of labels?). 
However it does not matter what form Rafinesque may have 
intended by Strophomenes rugosa, since he never described it. 
The genus must rest upon de Blainville's definition and figures, 
inadequate or erroneous though they be. These probably suit 
