62 
PALAEONTOLOGY OF NEW YORK. 
other two are to be referred to the same genus. Mr. Whitfield* has also der 
scribed a species, L. minima, from the Potsdam sandstone of New York. Adding 
to these the L. Morsensis ( Morsii ) of N. H. Winchell,! we find that the genus 
is thus far represented by six species, but of all these the interior characters 
of the typical species only are satisfactorily known. 
Genus B ARROISELL A, gen. nov. 
PLATE II, FIGS. 14-16. 
1S6S. Lingula, Meek and Wort hen. Geological Survey of Illinois, vol. iii, p. 437, pi. xiii, fig. 1. 
cnf. 1S66. Lingula , Davidson. British Silurian Brachiopoda, p. 42. 
cnf. 1870. Lingula, Winchell. Proceedings American Philosophical Society, vol. xiii, p. 24S. 
cnf. 1S73. Genus?, King. Annals and Magazine Natural History, Fourth Series, vol. xii, p. 13. 
cnf. 1881. Lingula ? , Davidson. Brachiopoda Budleigh-Salterton Pebble-bed, p. 361. 
cnf. 1887. Lingula (Glottidia ), Frech. Zeitschr. der deutsch geolog. Gesellseh., vol. xxxix, p. 392. 
Diagnosis. Shell externally as in Lingula. 
The pedicle-valve bears a high cardinal area, which does not appear to be a 
shelf, as in Lingula and Lingulella, but a thickened triangular plate, which is 
divided by a broad pedicle-groove. On the basal margin of the cardinal area, 
at the angles made by the lateral margins of the pedicle-groove, is a pair of 
bosses or condyles, which have undoubtedly served either as muscular fulcra, 
or, to some extent, as points of articulation with the opposite valve. The 
interior of the pedicle-valve shows a subquadrate depressed area lying directly 
beneath and almost in continuation of the pedicle-groove; this may represent 
the umbonal muscular scar. From its ante-lateral angles diverge two sharply 
defined, linear depressions, which extend about one-fourth the length of the 
shell and end abruptly. From outside and behind the extremities of these 
depressions, begins a pair of long, curved furrows, which are composed of two 
shorter curves, the posterior rounding over the extremities of the linear de¬ 
pressions referred to above, the anterior and longer curves gradually approxi¬ 
mating and nearly meeting at a point about one-third the shell’s length from 
the anterior margin. These furrows are accompanied by low ridges along their 
inner margin. A low median ridge, with elevated edges, begins at the posterior 
umbonal impression, and continues to the center of the valve, widening near 
* Bulletin American Museum of Natural History, vol. i, No. 5, p. 141, pi. xiv, figs. 1, 2. 1884. 
f Geology of Fillmore County, Minnesota. 1876. 
