40 THE NAUTILUS. 
Streptostyla turgidula (Pfr.) var. producta Pilsbry. One 
specimen. 
Succinea recisa Morelet. 
Aplexa impluviata laeta Martens. Appeared to be feeding 
on banana leaves which had been thrown into the pool. 
Planorbula obstructa anodonta (Pilsbry). Conchens river. 
Laevapex excentricus (Morelet). Pools by the railroad. 
Gundlachia hinkleyi Walker. With the above. 
Potamopyrgus coronata (Pfr.). Rio Conchens. 
Amnicola conchensensis Walker. Rio Conchens. 
Ampullaria flagellata lattret C. & F. On banana leaves and 
eull bunches of bananas which had been thrown away. 
Mycetopoda sp. Rio Conchens. This mollusk burrows 
head down until the posterior part is just above the bed of 
the stream; the foot is extended nearly the width of the shell 
farther down in the soil. When removing the first one found 
a strong pull tore the foot from the shell. 
Nephronaias ortmanni Frierson. Plentiful in Rio Con- 
chens; in one place several hundred were massed together. 
Glabaris depexa (Martens). With the above; only one 
found. 
Pisidium guatemalensis (Sterki). Rio Conchens. Sterki 
says: ‘‘Has a hinge of unique formation; width 5, height 4, 
diam. 8 mm.’’; fragile. 
Pisidium sp. With the above. Sterki says: ‘‘ Although of 
the same size and the same appearance, they are evidently 
distinct from Pisidium singleyi (Sterki). Of the same group, 
same shape and appearance with a Pisidiuwm from Barbados; 
unnamed, so far as I know.’’ 
Eupera yucatanensis minma (Pilsbry). Rio Conchens, 
scarce. 
Livineston. Beach and beach drift. 
Polygyra helictomphala (Pfr.). Only one specimen. 
Streptostyla ligulata (Morelet). ‘‘A very rare species’’ ; 
the only one found was at the edge of vegetation growth. 
Helicina flavida (Mke.) or H. trossula (Morelet). 
Helicina coccinostoma Morelet. First determination was 
H. oweniana. 
