THE NATURAL SCIENCE JOURNAL. 
31 
ville with Orthis insculpta, but I am con¬ 
fident the figures reproduced by Hall 
come nearer representing that fossil than 
any other one from the Silurian rocks of 
the Ohio Valley, notwithstanding the 
difference that may be distinguished, by 
reason of the larger deltidium or delthy- 
rium. 
This identification, if correct, does not 
destroy the genus Orthis or make Stro- 
phom.ena rugosa the type of that genus; 
it simply shows the folly of trying to 
restore old generic and specific names 
that were never defined or illustrated by 
the author himself. 
The history of the use of the word 
Strophomena, in America, may be briefly 
stated, as follows : In the Annual Re¬ 
port of the Geological Survey of New 
York for 1838, T. A. Conrad, who had 
in charge the pahcontological department, 
named as new species Leptsena alternata, 
L. deltoidea and L. semiovalis, the last 
one of which was regarded later as 
synonymous with Leptaena sericea. In 
the table of Organic Remains, in the 
report for 1839, he called these species 
Strophomena alternata and Strophomena 
deltoidea. These names were repeated in 
the Report for 1841. 
On the first of January, 1842, Ebenezer 
Emmons transmitted to the Governor of 
New York his Report on the Second Dis¬ 
trict, which was published the same year, 
in which he illustrated Strophomena 
alternata, S. deltoidea and S. nasuta. In 
January, 1842, Conrad read before the 
Academy of Sciences of Philadelphia his 
“ Observations on the Silurian and De¬ 
vonian Systems of the United States, 
with descriptions of new Organic Re¬ 
mains” (Proc. Acad. Nat. Sci., Vol. 
VIII., p, 228), in which he described 
and illustrated new species of Stropho 
mena, and among these are Strophomena 
camerata, S. tenuilineata and S. nasuta 
from the Trenton limestone, as well as 
others that have since been referred to 
other genera and he also referred to 
Strophomena alternata and S. deltoidea. 
In 1842, Vanuxem, in his Report on the 
Third District of New York, illustrated 
from the Clinton Group Strophomena 
depressa, which was reproduced in 1843 
in Hall’s Report on the Fourth District. 
The purport of all this would be, if 
Conrad had coined the word Stropho¬ 
mena, that S. alternata and S. deltoidea 
would be the types of the genus Stropho-. 
mena. The fact is, however, that Con¬ 
rad supposed Rafinesque had founded 
the genus Strophomena and he was 
applying it to congeneric forms. 
Prof. Hall, in 1847, in Pal. N. Y., 
Vol. I., used Leptsena instead of Stropho¬ 
mena, for these species, but in the syno¬ 
nyms, at the head of the descriptions, he 
gave references to the publications of 
Conrad and Emmons where they had 
used Strophomena. When, however, 
the 12th Report of the N. Y. St. Mus. 
was published, he corrected the nomen¬ 
clature of Volume I. and used Stropho¬ 
mena, for S. alternata, S. deltoidea and 
kindred species. From that time down 
to 1892, all palaeontologists of the United 
States used Strophomena instead of Lep- 
taena of these forms. 
The first palaeontologist appointed on 
the Geological Survey of Canada was E. 
Billings. In the Report of Progress for 
the year 1858, in the Reports of both 
Billings and Richardson, Leptaena sericea 
and Strophomena alternata are mentioned 
as constituting part of the fauna of the 
Chazy, Black River and Trenton Groups. 
