= 4 Ae 
transmitting the human and domestic animal liver flukes, are the species 
Fossaria truncatula, F, ollula, and Radix natalensis, All three species 
are sometimes placed in the genus Lymnaea, 


Fossaria truncatula (Muller) 
Pilate Visa Et 
Shell small, perforate, opaque, moderately glossy, without regular spiral 
striae. Its color is whitish to pale horn, The sutures are impressed, the 
columella straight, without a plait. The aperture is ovate, less than 1/2 
the height of the shell, its outer lip sharp, the columellar lip reflected. 
Adults (with about 6 whorls) measure 8-12 mm, in length. 
Distribution; Europe, eastern and Central Asia, Asia Minor, North Africa. 

Fossaria ollula (Gould) 
Figure 16 
Shell similar to F, truncatula, but more globose, with a relatively larger 
body whorl and aperture (aperture length more than 1/2 the length of the 
shell), and somewhat darker in color (usually light brown). Sometimes a 
very slight columellar plait tends to be present, Adults (with about 6 
whorls) measure 10-13 mm, in length. 
Distribution: China, Japan, Introduced in Hawaii. 

Figure 16. - Shell of Fossaria ollula (Gould). 

