226 MYA, 
carinata, shell oblong-oval, two-angled before, 
rayed, hinge-margin strait, compressed, keel- 
form ; teeth finely striate ; shell elongated trans- 
versely ; epiderniis greenish-yellow with broad 
dark-green rays 3 surface glabrous ; white, ira- 
descent within. Dimensions about three inches 
by two. 
Srelonga, shell much elongated transversely, nar-. 
row, thick, tumid, beaks flat ; lateral tooth 
long, thin ; purple within ; epidermis blackish- 
brown with fine interrupted wrinkles in longi- 
tudinal rows. Dimensions about three inches 
by one and a quarter. 
gibbosa, shell elongaied transversely, thick gib- 
bous; lateral teoth very thick, incurved ; pur- 
ple within ; shell thick and heavy, suddenly 
narrowed so as to appear beaked before, nar- 
vow and rounded behind, so as to appear sub- 
cylindric 3 epidermis blackish-brown finely stri- 
ated and deepiy wrinkled transversely ; purple 
within; lateral tooth very thick. Dimensions 
about four inches by two. 
cuneata, shell ovate, wedgeform, thick, gibbous ; 
disks tumid, anterior lunule furrowed ; lateral 
tooth thin ; purple inside; shell elongated, sub- 
triangular, thick and heavy ; beaks low and 
distant 3; epidermis blackish-brown, subferru- 
ginous, surface in fine wrinkles. Dimensions 
three inches and three quarters by two anda 
quarter. 
vadiata, shell broad-ovate, thin, finely striated, 
glossy rayed; biuish-white within, or tinged 
~ with red; shell with the anterior side broad 
ihin, fragile; beaks slightly elevated and ap 
