MYA, - - Bes 
proximated ; epidermis greenish-yellow or ol- 
ive-brown, with dark-green rays finely striated 
transversely ; surface smouth and shining. Di- 
mensions about one inch and a half by two and 
a half. 
mucronata, shell ovate, broader behind ; base 
compressed, faicate ; beaks small, elevated, 
acute ; purple within ; anterior lunule long, 
posterior one small; epidermis horu-colour and 
obscurely rayed, smooth. Dimensions one inch 
and a quarier by two and a quarter. 
inflata, shell oval, thick, tumid ; beaks broad ob- 
tuse behind, wedge-form before ; pearly-white 
within; epidermis yellowish-green, rayed. Di- 
mensious one inch and three quarters by three 
and a quarter. 
ventricosa, shell large, thick, triangular, ovate, 
convex ; bosses large, round, prominent ; beaks 
recurved ; cavity capacious ; epidermis yellow- 
olive, with green rays; surface smooth and 
shining ; pearly-white within. Dimensions 
about three inches by four. 
siliguoidea, shell loug-ovate, subcylindric, thick, 
regularly rounded, rayed; beaks elevated ; cavi- 
ty small; inside white ; epidermis yellowish- 
olive, rayed with distant dark-green lines. Di- 
mensions two inches by three and a quarter. 
plana, shell rhomb-oval ; thin, beaks depressed ; 
disks flattened compressed ; teeth slightly ele- 
vated, smooth ; epidermis brown-yellow, deeply 
wrinkled Dimensions two inches and three 
fourths by four and three fourths. | 
triangularis, shell triangular, gibbous-inflated, ray- 
ed, gaping ; anterior ae flattened, ribbed, can- 
