Identification
Many snails are very difficult to distinguish from one another because there are so many physical similarities between them. However, there are small physical characteristics that makes each species of snails individualistic.
Many of the snails in Texas and southeastern United States who where recently assigned to the genus Polygyra were found to actually belong to a total of 4 genera; Polygyra, Daedalochila, Millerelix, and Lobosculum (Pratt, 1981). Linisa is a subgenus that falls under Polygyra and can mainly be distinguished by its sexual organ (Pratt, 1981).
There are only two species of snails that fall under the genus Linisa; L. tamaulipasensis and L. texasiana. Both snails are very similar, however, there are some small differences that allow these snails to be distinguishable. Linisa tamaulipasensis are grey in color while the L. texasiana are more brownish yellow in color (Hubricht, 1962). L. tamaulipasensis have a more depressed shell with a smaller umbilicus compared to the L. texasiana (Hubricht, 1962). The parietal tooth, which is located near the foot, is longer, higher, and straighter with the outer edge extending slightly past the lower end of the lip (Hubricht, 1962). Also, the parietal tooth can always differentiate the two species of snails because the L. tamaulipasensis has a tooth on the upper end of the parietal tooth (Hubricht, 1962).
