* 
The Shell-Collector’s Handbook. 59 
NERITINA FLUVIATILIS, LINN. 
SHELL semi-globular, slightly oval, solid, glossy, yellowish 
or brownish, spotted with white, brown, purple or pink, 
and marked with fine but distinct plaits; spire short, 
lateral; composed of three whorls, the last one being 
excessively disproportionate ; mouth transversely semi- 
lunar; operculum semilunar, yellowish, with an orange 
border, and underneath a strong, raised, grooved spire 
placed at one end. Animal white, head and back of the 
neck blackish; hinder part of the foot sometimes black- 
spotted; tentacle long, white, with blackish line. 
Habitat—In canals and rivers with stony bottoms. 
v. cerina (Coldb.): Shell of an uniform straw-yellow 
colour. 
v. nigrescens (Colb.): Shell black or blackish. 
v. trifasciata (Colb.): Shell ornamented with three 
spiral dark bands. 
v. undulata (Cold.): Shell with some transverse dark 
bands. 
