264 
Aug. F. Foerste 
Clidophorus planulatus, Orthoceras lamellosum, Cornulites of 
straight free type, resembling T entaculites , Calymene, and Tri- 
nucleus. 
Another nasute form of Rafinesquina was found at Worthville, 
associated with Plectambonites, Dalmanella, Bys^onychia radiata, 
Modiolopsis modiolaris, Orthodesma nasutum, Clidophorus planu- 
latus, Ctenodonta lorrainensis, Lyrodesma poststriatum, Hormo- 
toma, Cyrtolites ornatus, Cornulites of straight free type, resembling 
Tentaculites, Calymene, and Trinucleus. 
It is not likely that these nasute forms constitute a species dis- 
tinct from Rafinesquina alternata as identified from the same beds, 
but their distribution at about the same horizon is possibly of 
significance for stratigraphic purposes. 
Rafinesquina alternata was figured by" Emmons from the Tren- 
ton of New York and the Trenton form is to be regarded as the 
type of the species. With this Trenton form it has been cus- 
tomary to identify all related forms in later rocks, up to the 
close of the Richmond. The discrimination of these forms into 
species and varieties is highly desirable. 
9. Rafinesquina squamula, U. P. James 
{Cincinnati Quarterly Journal of Science, vol. 1, p. 335, 1874) 
Shell small, thin, semi-oval in outline, broader than long; hinge- 
line varying from a little more to a little less than the greatest 
breadth of the shell farther forward. 
Dorsal valve slightly concave or nearlj^ flat; cardinal line 
straight; cardinal area linear; a slight depression immediately 
forward of the beak. Surface covered, with fine, rounded radiat- 
ing striae of nearly uniform size, increased toward the free margin 
by bifurcation. 
Ventral valve slightly convex; beak and hinge-line slightly pro- 
jecting; cardinal area narrow, a little the widest in the middle; 
foramen triangular and nearly closed by the cardinal process of 
the other valve; a strong mesial rib extending from the beak to 
the front; surface covered by fine, rounded, radiating striae, which 
bifurcate once or twice before reaching the free margins; the 
striae starting at and near the beak more prominent than the 
branching ones; crossed by very fine concentric lines, visible only 
