214 
A ug. F. Foerste 
Fifteenth Report of the same series of publications, 1862, figs, i, ; 
2 and 3 on plate 2 are intended to illustrate this species. These ! 
figures differ considerably in outline; hence, fig. i is taken as the i 
type. It evidently represents a brachial valve having a subquad- 
rate outline, with a length equalling about three-fourths of the j 
width. The type from which this figure was prepared is pre- ji 
served in the American Museum of Natural History, in New i| 
York City. It evidently belongs to the coarsely striated forms f 
usually listed under Dalmanella emacerata, and the coarseness of l[ 
the striations is well represented by fig. i, on plate 2 of the Fif- i 
teenth Report. In these forms about 8 to 10 striations occupy I 
a width of 5 millimeters along the anterior margin of shells having |l 
a width of 20 millimeters. i 
Geological position. The type was received from Mr. Carley, ji 
and came from the Cincinnati Group, at Cincinnati, Ohio. The 1 ; 
exact horizon from which the type came is unknown. Specimens j 
having the same characteristics as the type were collected by Bass- ! 
ler and Albers in the Friarthrus hecki horizon, or Fulton layer, f 
at the base of the Eden formation. This Fulton layer is approx- i 
imately equivalent to the Utica of New York. Specimens from |; 
this horizon are here regarded as typical. Specimens not dis- I! 
tinguishable from the typical form have been received from various 
collectors from elevations of 60, 75 and 150 feet above the base of I 
the Eden. This would extend its range into the Lower and j 
Middle Eden. Further collecting from definite horizons is neces- ! 
sary. None of the forms figured by Meek as Orthis emacerata j 
belong to this species. I 
Dalmanella emacerata — filosa. | 
{VI ate IV. Fig. l ) [ 
Some of the specimens referred to Dalmanella emacerata differ ' 
from the type in having considerably finer and more numerous ji 
striations. The specimen here figured, magnified 1.6 diameters, | 
collected by Bassler from the Triarthrus becki horizon at Cincin- !i 
nati, has 14 to 16 striations in a width of 5 millimeters. A sim- ! 
ilar specimen was found 150 feet above the base of the Eden. I 
LTtil additional material has been collected it must remain doubt- | 
ful whether these more finely striated forms should receive any 
separate designation. i 
i 
