40 THE NAUTILUS. 



Streptostyla turgidula (Pfr.) var. producta Pilsbry. One 

 specimen. 



Succinea recisa Morelet. 



Aplexa impluviata la-eta Martens. Appeared to be feeding 

 on banana leaves which had been thrown into the pool. 



Planorbula obstruct a anodonta (Pilsbry). Conchens river. 



Laevapex excentricus (Morelet). Pools by the railroad. 



Gundlachia hinkleyi Walker. With the above. 



Potamopyrgus coronata (Pfr.). Rio Conchens. 



Amnicola conch en sen sis Walker. Rio Conchens. 



Ampullaria flagellata lattrei C. & F. On banana leaves and 

 cull 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 01 

 found. 



Pisidium guotemalensis (Sterki). Rio Conchens. Sterki 

 says : ' ' Has a hinge of unique formation ; width 5, height 4, 

 diam. 3 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 Pisidium from Barbados ; 

 unnamed, so far as I know. ' ' 



Eupera yucatanensis minima (Pilsbry). Rio Conchens, 

 scarce. 



LIVINGSTON. 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. 



