366 
PALEONTOLOGY OF NEW YORK. 
seven coarse, often irregular plications, only a part of them reaching the 
beak. 
The brachial valve is depressed-convex, with a conspicuous median fold, 
grooved longitudinally and bounded by deep marginal depressions. The lateral 
slopes are more convex than on the other valve, but are similarly plicated. 
Surface of the valves usually without concentric growth lines. 
An average example has a length of 8 mm. and a greatest width of 7 mm. 
Hudson River group. Near Edgewood, Pike county, Missouri. 
Camarophoria rhomboidalis, sp. nov. 
PLATE LXII, FIGS. 25-29. 
Shells of rather small size, subtriangular in outline with cardinal margins 
extending for half the length of the valves. Pedicle-valve with apex scarcely 
elevated, incurved, with deltidial plates usually concealed; slightly convex 
about the umbo, broadly depressed medially, forming a sinus which makes a 
linguiform extension on the anterior margin. This sinus may bear one and 
sometimes traces of two other low plications. The lateral slopes are smooth, 
except at the margins, where there is faint evidence of one or two plications on 
each. The brachial valve is convex and broadly rounded with abrupt umbo- 
lateral slopes; broad, low median fold, apparent only in the pallial region, and 
bearing a median plication. Traces of two lateral plications are visible at the 
margin of the valve, and these are somewhat more distinct on the surface than 
on the opposite valve. Surface smooth or with fine concentric lines. The in¬ 
terior structure of the shell is normal for this genus. 
Corniferous limestone. Cass county, Indiana. 
Parastrophia divergens, sp. nov. 
PLATE LXIII, FIGS. 4-7. 
Shell of medium size with strongly convex brachial valve and depressed 
convex, anteriorly concave pedicle-valve. The beak of the pedicle-valve is 
erect, but not conspicuous ; from the gently convex umbo the surface slopes 
