206 FIELD COLUMBIAN MUSEUM ZOOLOGY, VOL. VII. 



on plants and rocks. This species deposits its eggs in January 

 and February. The eggs are very large and are usually attached 

 to the under side of rocks. This species is so abundant that its 

 large gelatin-like eggs would furnish a considerable amount of 

 food for small fishes. It is a very abundant species in Guatemala 

 and San Salvador to Central Nicaragua. 



Family Amnicolidse. 



Amnicola guatemalensis Fisch & Crosse. 



A very small species and very scarce. Of no economic import- 

 ance. 



Amnicola petensis Morelet. 



Very small and very scarce. Of no value. 



Family Limmeida*. 



Ancylus excentricus Morelet. 



Very small and very scarce. It is found attached to rocks. 



Planorbis subpronus Von Martens. 



Very small, rather common. Of no economic importance. 



