THE NAUTILUS. 719 
aperture, no spiral striation, and is smaller. P. fieldii Tryon 
is a much smaller shell without spiral lines, and higher relative 
to its diameter. 
Probably all of this group should be regarded as toothless 
forms of Planorbula. 
GUATEMALAN NOTES. 
BY A. A. HINKLEY. 
Coelocentrum yigas Von Martens, identified by Dr. H. A. 
Pilsbry as a dark variety,’ is the largest land shell the writer 
ever had the pleasure of hunting. On Feb. 20, 1913, the first 
dead specimen was found by a large log in a banana field. 
Probably an hour was spent searching for a live one but with- 
out success. Leaving the banana field, I followed up a branch 
of the Cavech River to where it issued from the mountain side. 
The labor of working through jungle and over rocks was re- 
warded by finding the finest specimens of Pachycheilus indiorum 
which I secured. From here the return was around the side of 
another mountain, heavily wooded; on this mountain 5 living 
C. gigas were found. This was considered a great find. 
The next day another place was visited beyond the mouth of 
the Cavech River to where the mountain came out to the shore 
of the gulf. After working through the thick undergrowth at 
the foot of a mountain, the vegetation was more open, making 
it easier to climb up or down. The first shell found was a fine 
C. gigas in the act of depositing eggs in a round pit about ? of 
an inch across, and probably a half-inch deep, scooped out of 
the mellow earth and containing 35 to 40 eggs. 
The best part of the day was spent on this mountain, looking 
for these shells, of which 19 were secured. They were nearly 
always partly covered with leaves. No more nests of eggs were 
found, but others were seen which had been destroyed by some 
enemy. 
1The specimens are not ‘‘ yellowish gray,’’ 
but between walnut brown and burnt umber. 
as von Martens described it, 
