haa 
Radix natalensis (Krauss) 
Figure 17 
Shell small to medium, very thin, narrowly perforate or imperforate, 
translucent, moderately glossy, whitish to light brown or horn, sculptured 
with minute spiral striae. The spire is short with moderately impressed 
sutures; the body whorl and aperture are very large (the aperture length 
is more than 2/3 the height of the shell), the aperture ovate-lunate with 
sharp lips. The columella is twisted into a distinct plait. Adults (with 
4-5 whorls) measure 15-25 mm. in length. 
Distribution: Africa, Madagascar. 

Figure 17. - Shell of Radix natalensis (Krauss). 
Family PLANORBIDAE 
This family contains mostly discoidal species, but a few, such as 
Physopsis africana and Bulinus truncatus, are oval or elongate, The 
snails that carry the human blood fluke in Africa, South America, and the 
West Indies belong to this family. 
