288 
PALAEONTOLOGY OF NEW YORK. 
it be found desirable or important to recognize the value of the characters above 
indicated, these forms may be separated under the term Leptostrophia. 
As typical representatives of this group, may be taken S. magnified, Hall, of 
the Oriskany sandstone, and S. perplana, Conrad, of the Corniferous, Hamilton 
and Chemung faunas; and of the other American representatives we may cite 
S. textilis, Hall, of the Coralline limestone, S. Becki, Hall, of the Lower Helder- 
berg, S. magniventra, Hall, of the Oriskany, S. Junia , Hall, of the Hamilton, S. 
Irene, S. Blainvillii and S. Tullia, Billings, from the Lower Devonian of Gaspe. 
In European faunas the group is represented by Strophomena filosa, (Sowerby) 
Davidson, of the Wenlock, S. explanata, (Sowerby) Kayser, of the Coblenzian, 
S. ? palma, Kayser, of the Calceola beds, and S. Steini, Kayser, of the Wiedaer- 
schiefer (Lower Devonian) of the Hartz 
There is a small number of species, the incipient members of the genus 
Stropheodonta, in which the delthyrium is open, or but partially covered, as 
in some of its later forms, the crenulations are confined to a very limited ex¬ 
tent on either side of the deltidium, and upon one of these forms, Strophomena 
Leda, Billings, from the Anticosti group, Professor 
Shaler has proposed to found* the genus Brachyprion. 
To the same group belong the Strophomena Philomela, 
Billings, from the Pentamerus oblongus beds of Anticosti, 
and Professor Shaler has described two other species 
from Anticosti, Brachyprion ventricosum and B. genicula- Fig . 2 i. Brachyprion Leda. 
turn. These features can scarcely be regarded as of 
generic value, but the group is an interesting one on account of its being the 
precursor of the fuller development of those characters on which the genus 
Stropheodonta was originally founded. 
Dr. CEhlert has proposed the generic term Douvillina,! for the species 
Leptcena Dutertrii, Murchison,J evidently not fully apprehending its very close 
* Bulletin of the Museum of Comparative Zoology, vol. i, p. 63. 1865. 
f In Fischer’s Manuel de Conchyliologie ; Brachiopodes, p. 1282. 1887. 
I See de Verneuil, Geologie de laRussie, etc., p. 223, pi. xiv, figs. 2 a, b, c. Fig. 4 of the same plate 
represents an interior closely similar to that figured by CEhlert, and in the explanation of plate is referred 
to L. Dutertrii, but on page 224 is regarded as belonging to L. asella, de Verneuil. In this case the latter 
