46 THE NAUTILUS. 
Nephronaias dysom (Lea). Found with the above. They 
were always more or less eroded, a good species. This stream 
is some five miles west of Esmeralda and the above two species 
were the only ones found there. 
Potamopyrgus coronatus nicaraguanus (Ancey). Plentiful 
in small bays or recesses of the river. 
Cochliopa dulcensis Marshall. Common with the other 
small species taken with a net. 
Cochliopa izabal Pilsbry. Common. 
Neritina lineata reticulata C. & F. 
Neritina listeri Pfr. Both these Neritina were scarce. 
Planorbis caloderma Pilsbry. A small species, little larger 
than Segmentina obstructa, with more tumid whorls. 
Cyrenoides guatemalensis Pilsbry. One specimen, 
Mytilopsis sallei (Recluz). Numerous, on sticks and stones, 
often in clusters of many individuals. 
JocoLo. This plantation, on the north side of Lake Isabal, 
is owned and operated by Mrs. Potts, a hospitable lady. The 
commodious residence among palm and citrus trees is pic- 
turesque viewed from the small wharf projecting into the 
lake. The lake is bordered by rushes, with here and there 
small open beaches of sand. On a point some distance above 
the wharf was a windrow of fine drift, thrown up by a strong 
wind; this was the only place where drift was found. It eyi- 
dently came down a river near by. This proved quite rich in 
number of species, but specimens were scattering. The entire 
windrow was worked over. The region has numerous small 
streams with beds of rock, gravel and sand, with soft mud 
where they enter the lake. 
Nephronaias guatemalanus (von Martens). A few speci- 
mens referred to this were found in the lake with N. ravis- 
tellus. It is some higher and lighter colored than that species. 
Nephronaias ravistellus (Morelet). Common. In 1914 they 
were found mostly in water two to four feet deep, but in 1917 
they were plentiful among the rushes and on the sandy beach 
up to the water’s edge. 
Nephronaias tabascoensis (Kiister). Mrs. Potts gave the writer 
a few found by a native. 
