Distinguishing heliscma [seminolina] Duryi from biomphalaria Alexandria in Egypt

A relationship between the height [H] and diameter [D] was extracted for distinguishing the shells of Helisoma duryi and Biomphalaria Alexandrina, which are similar in general appearance. This relation is expressed as follows: In juvenile snails: H. duryi [H = 0.44 D + 1.7] and B. Alexandrina [H = 0.3 D + 0.7]. In older snails: H. duryi [H = 0.3 D + 2.5] and B. alexandrina [H = 0.2 D + 1.54]. The difference in structure is also given