i6 
BULLETIN OF THE LABORATORIES 
b. 
C. 
9. P. RUSHVILLENSIS. Her. 
(= ? P. morbilliani. Win.'* 
Surface pustulose, spines scattered. 
10. P. SHUMARDIANUS. 
Beak truncated, much as above. 
11. P. CURTIROSTRIS. Win. 
C. Surface slightly convex, with nearly equal radiating and con- 
centric striae. 
12. P. NODOCOSTATUS. 
This list might be extended but some uncertainty would be introduced. 
The above species can be recognized with tolerable certainty. No. i, occurs in 
division III, P. nebrascensis is perhaps not found in the the Waverly, the species 
so identified being possibly peculiar forms of P. newberryi. P. semireticulatus 
occurs in the upper part of division III, while its close ally, P. newberryi belongs 
in a lower zone in division I, but the two species seem to pass into each other in 
the northern part of the state. P. flemingi, var, burlingtonensis H, is from the 
uppermost horizon of division III. P. rushvillensis and P. shumardiana are very 
closely related, though the former is from the highest horizon of divison III and 
the latter seventy feet below conglomerate II. P. raricosta is known only thus 
far from below the last mentioned horizon. 
Genus Rhynchonella 
It is not at present possible to catalogue the Rhynchonellidae of 
the Waverly with any degree of success. Three types are easily sep- 
arable. 
A. Large species with three to four plicae on the fold and sinus. 
1. R SAPPHO. 
2. R. SAGERIANA. 
B. Rather large species with five to eight plicae on the fold and sinus. 
a. Abrutly deflexed around the front. 
3. R. MARSHALLENSIS. 
b. 4. R. COOPERI. 
C. Smaller species with two to four sharp plicae on the deep fold. 
5. R. CONTRACTA. 
D. Small spcies with slight or no fold. 
6 . ? 
LINGULA ATRA.Sp.n. 
(Plate X, Fig. 30.) 
Ventral valve rectangularly sub-elliptical, length to width as 9 to 
5, sides parallel, front margin truncate, cardinal slopes forming nearly 
a right angle, unbonal region rather distinctly convex, triangular area 
from front to beak flattened, lateral aspects gently sloping, dorsal valve 
