90 
BULLETIN OF THE LABORATORIES 
GENUS RHYNCHONELLA, Fisher. 
XV. Rhynchonella scobina, Meek. 
Described in Ohio Pal. Vol. I and II. 
Locality and position. Soldiers’ Home, Huffman, and Centreville 
Quarries, Clinton Group; common. 
genus ZYGOSPIRA, Hall. 
XVI. Zygospira modesta, Say {sp.). 
{Plate XIII, Fig. 6.) 
Described in Ohio Pal. Vol. I., and mentioned as occurring in 
the Clinton Group. I have seen no specimens which could be re- 
ferred without doubt to this species unless it be a dorsal valve of the 
following description. 
Dorsal valve subquadrate orbicular; beak not elevated; marked by 
about twenty simple plications; with a shallow mesial sinus, occupied 
by three plications, the middle plication larger, the lateral ones 
smaller than the plications immediately adjacent. 
Length, 7 mm.; width scarcely larger. 
Locality and position. Beavertown marl, Huffman’s Quarry, Clinton 
Group. 
genus ATRYPA, Dalman. 
XVH. Atrypa nodostriata. Hall. 
{Plate XIII, Fig. ().) 
Shell described in Ohio Pal. Vol. H. 
A small species of Atrypa referred here occurs sparingly, of the 
following description. 
Shell oval, marked by plications, branching near the middle of the 
shell. Mesial sinus on the ventral valve plainly defined by the 
bordering plication on each side, containing three to five plications. 
Dorsal valve with mesial elevation, well defined by a more or less 
sharp sinus on each side, which is more marked towards the beak. 
Length, ii mm.; breadth, ii mm.; convexity, 6 mm. 
Locality cind position. Soldiers’ Home, Clinton Group. 
