FOSSILS OF THE CARBONIFEROUS. 247 
Genus SANGUINOLITES McCoy. 
In the absence of the structure of the hinge-line, the muscular scars, 
and pallial impression in the following species, there is some uncertainty in 
referring them to this genus, as in their general external appearance they 
resemble more or less forms referred to the Modiomorphide. 
Sanguinolites Holus H. & W. 
Plate xx, figs. 6, 7, 9. 
Sanguinolites wolus Hall, 1870. Prelim. Notice Lam. Shells, p. 46. 
? wolus Meek, 1875. Pal. Ohio, vol. ii, p. 307, pl. xvi, figs. lac. 
Aolus Hall, 1883. Pal. N. Y., vol. v, pt. 1, Plates and Explanations, 
pl. Ixvi, figs. 31-35, 43. 
The specimen illustrated by fig. 6 is a typical form of this species, cor- 
responding to those from the Waverly sandstone of Ohio, and we cannot 
distinguish the shorter, broader shells, as shown by figs. 7 and 9, as a dis- 
tinct species, as there is a complete gradation of form between them, and 
to even astill broader variety that is designated in the systematic list as 
S. Holus, var. A small shell of this species from the same locality resembles 
very closely some examples of Sanguinolites rigidus, an illustration of which 
is given from the Devonian limestone on plate xvi, fig. 6. 
Formation and locality—Lower portion of the Carboniferous Group on 
the east slope of a small conical hill on the east side of Secret-canon-road 
Canon, Eureka District, Nevada 
Sanguinolites retusus, nD. sp. 
Plate xx, fig. 10. 
Shell broad, irregularly ovate; moderately convex; beaks anterior, 
small and compressed; umbonal slope distinctly angular and extending 
from the beaks to the postero-basal angle, the somewhat rapidly sloping 
postero-cardinal slope being marked midway by a slight longitudinal ridge. 
Cardinal line short and a little arcuate; basal line broadly rounded, uniting 
posteriorly with the slightly rounded, oblique posterior line to form a 
