226 
PACIFIC SCIENCE, Vol. 1, October, 1947 
U.S.N.M. 90301, 1 specimen from the Philippines. 
U.S.N.M. 304240, 1 specimen from Japan. 
US.N.M. 344828 (Hirase 2812), 3 specimens 
from Osima, Osumi, Japan. 
Corculum levigatum, new species 
(Plate 1, Figure 1) 
This species resembles C. monstrosum, 
but differs from it in being flatter, with the 
margin not denticulate. The anterior side is 
moderately elevated at the ventral edge. The 
outer margin is decidedly upturned, a shape 
which lends the side of the shell a dished 
appearance. The surface is marked by strong 
radiating cords, the inner of which are 
weakly nodulose, while the outer are devoid 
of them. These cords are separated by 
spaces equaling the cords. Both the cords 
and the spaces between them are marked by 
fine threads that parallel them, and by very 
regular transverse incremental lines which 
are closely spaced and only a trifle stronger 
than the threads. The posterior surface is 
marked by low, broad radiating cords sepa¬ 
rated by shallow spaces a little narrower 
than the cords. Of these cords, those near 
the escutcheon show only traces of denticles. 
The finer radial sculpture is almost absent, 
while the incremental markings are very 
regularly spaced threads separated by spaces 
as wide as the threads. 
The type, U.S.N.M. 343365, was obtained by 
the U. S. Exploring Expedition and bears no spe¬ 
cific locality label. It measures: height, 47.5 mm.; 
length, 20.1 mm.; diameter, 43.4 mm. 
In addition to the type I have seen the follow¬ 
ing specimens: 
U.S.N.M. 7673, 2 additional specimens from the 
same source. 
U.S.N.M. 17467, 1 specimen from the East 
Indies. 
U.S.N.M. 2544, 1 specimen obtained by the U. S. 
Exploring Expedition in the East Indies. 
U.S.N.M. 168709a, 1 specimen from China. 
U.S.N.M. 344829 (Hirase 2813), 1 specimen from 
Osima, Osumi, Japan. 
Corculum aselae, new species 
(Plate 2, Figure 1) 
This species has the anterior side mod¬ 
erately dished, but the extreme edge in 
mature shells is bent posteriorly; the pos¬ 
terior side is also rather strongly ridged 
radiately. In some features it recalls C. 
levigatum, but the latter has the posterior 
side uniformly dished and much smoother. 
The color of this species is extremely 
variable, ranging from white through yellow 
and orange to rose. These shades may ap¬ 
pear in more or less solid tints or in inter¬ 
rupted or continuous rays or bands. 
The anterior side is convex on the inner 
half, then gradually becomes concave on the 
rest of its surface. It is marked by strong 
radiating ridges which are about as wide as 
the spaces that separate them. The inner of 
these cords are strongly nodulose, but the 
nodules gradually become weaker outwardly 
until they are scarcely perceptible on the outer 
cords. Fine threads paralleling the ridges are 
present in the spaces between the cords, while 
weak incremental lines cross them. The pos¬ 
terior side is well elevated adjacent to the 
escutcheon and here bears four low, rather 
broad, weakly nodulose radiating ridges. 
Outside this area the shell is less convex, 
with the outer edge slightly upturned. This 
surface is marked by depressed radiating 
ridges separated by mere impressed lines, 
and by very regular slender, closely spaced 
incremental threads. 
The type, U.S.N.M. 543566 (Franco 3 d), 
measures: height, 44.2 mm.; length, 17.8 mm.; 
diameter, 38.3 mm. (Near Cebu City, Cebu.) 
In addition to the type, we have the following 
specimens: 
U.S.N.M. 543567 (Franco 3c). 
US.N.M. 543568 (Franco 3 h). 
U.S.N.M. 543569 (Franco 3m). 
US.N.M. 543570 (Franco 1c). 
U.S.N.M. 344829 (Hirase 2813), 1 specimen col¬ 
lected at Osima, Osumi, Japan. 
