BRACHIOPODA. 
259 
Observations. The distinguishing characters of this genus are, ( a ) its orthoid 
external features, and muscular scars in the pedicle-valve ; ( b) the presence of 
strong dental lamellae which are not known among the streptorhynchoids, ex¬ 
cept in Meekella ; (c) the absence of any cardinal area on the brachial valve; 
(d) the presence of a slight median septum in both valves. Hipparionyx proximus 
is an abundant fossil in the Oriskany sandstone of New York, occurring also at 
Cumberland, Maryland, and in the arenaceous layers at the base of the Upper 
Helderberg in the Province of Ontario. The form from the Eifel referred to 
this species by Schnur is regarded by Kayser* as Orthothetes umbraculum, and the 
shells thus identified by Davidson, from the beds of Looe, Cornwall, and the 
Budleigh-Salterton pebbles, can not belong to the Oriskany species. 
Genus KAY SERELLA, gen. nov. 
1853. Orthis, Schnur. Palseontographica, vol. iii, p. 212, pi. xxxvii, fig. 3; pi. xxxviii, fig. 4; p. 218, 
pi. xlv, fig. 9. 
1871. Streptorhynchus ?, Kayser. Zeitschrift der deutschen geologischen Gesellsehaft, vol. xxiii, p. 617, 
pi. xiv, figs. 2 a, b, c, d, e. 
1885. Streptorhynchus 9, Maurer. Kalke von Waldgirmes, p. 138, pi. v, fig. 10. 
1886. Streptorhynchus ? , Wenjukoff. Fauna des Devon. Syst. im nordw. und central Russl., p. 55, 
pi. ii, fig. 4. 
The species described as Orthis lepida by Schnur, in his work on the Brachi- 
opoda of the Eifel, f has been shown by Professor Kayser to be a streptorhynchoid 
shell, with a covered delthyrium on the pedicle-valve and a very prominent 
median septum in the brachial valve, dividing the internal cavity much as in 
the Devonian forms of Scenidium, where the central plate is greatly developed. 
This is a feature not met with elsewhere among the fossils of this group, and 
though the internal characters of the species remain undefined, except the sep¬ 
tum, this character alone must exclude it from any of the generic groups now 
recognized. That Professor Kayser recognized its generic value, is evident 
from his language : 
“ Strept. lepidus steht durch Gestalt, Form der Rippen und deutliche Perfora¬ 
tion der Schale den Arten des Formenreihe der Orthis circularis zwar nahe, 
* Zeitschr. der deutschen geologischen Gesellsehaft, vol. xxiii, p. 615. 1871. 
t Zusammenstellung und Beschreibung sammtlicher im Uebergangsgebirge der Eifel vorkommenden 
Brachiopoden, nebst Abbildungen derselben; Palseontographica, ut. cit. 
