396 TRANS. OF THE ACAD. OF SCIENCE. 
a long, narrow pseudo-deltidium, marked with distinet arched 
strie ; apex nearly or quite I, Or obliquely truncated and 
some times excavated in front. Surface marked with coneen- 
very distinct) ruge, hick are most prominent, and assume a 
somewhat varicose appearance, near the base. Smaller valve 
very gently ree surface markings obliterated. Interior 
characters unknown 
Din ensions, a Hel eight of larger valve about 14 inches; 
width at base, about 1 inch. 
Locality — White Limestone, Guadalupe ‘Mountain; 
_ ACEPHALA. 
Genus Myatina. 
M. squamosa, Sow., Trans. Geol. Soc., Loe Vol. 
3, p. 120. 
Our shell from the White Limestone of the 
Mowstaing 
tains agrees — Seer with the ‘eset sod ig 
— he! this King and others. 
gral at and st Med 
sp 
ton and a cite the sam 
the Permian of 
M. acts 5, Shumar, Trans. Acad. ape St. ig vas 
NT: is, Meek and Hs: dey Trans - 
po tot Beira). ; : ee 
