104 GLOSSAKY. 



conoidea, cone-like. 



contecta, covered. 



contortus, twisted together. 



contractile, able to become shorter. 



convex, bulging out. 



corneus, horny. 



cbrvus, a crow, applied to a very dark var. of L. palustris. 



costdta, ribbed. 



cristdta, crested. 



crystdllinus, crystalline. 



curia, short. 



curvirostris, with curved "beaks. 



Cyclostoma, round mouth ; name of a genus. 



Gyclostomatidce. Name of a Family of mollusks, from the 



typical genus Cyclostoma. 

 cygnea, belonging to swans. 



D. 



deciduous, liable to fall off. 



decolldta, shortened from the top, truncated. 



decussated, intersected by cross-lines. 



denticle, a small tooth. 



dentition, see lingual. 



depressa, flattened. 



depressiuscula, somewhat flattened. 



dextral. A univalve is said to be dextral when the mouth 



opens to the observer's right as he holds it with the 



spire pointing upwards. 

 dextrorsa, turned to the right hand. 

 dilatatus, expanded. 

 Dillwynii, named after Dillwyn. 

 disciformiSj formed like a circular plate. 



