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Biometrical Observations on Shells of Limnaea Species

Published online by Cambridge University Press:  05 June 2009

B. G. Peters
B. G. Peters
Affiliation:
Principal Research Assistant, Institute of Agricultural Parasitology, St. Albans
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Extract

1. In differentiating between species of snails various ratios of shell dimensions are frequently used as biological constants descriptive of the species. Some of the ratios commonly used are: length to breadth (L/B), length to length of body-whorl (L/W), length to length of shell aperture (L/l), and length of shell aperture to its breadth (1/b). Mean and extreme values of these ratios are given for small samples of five species of Limnaea.

2. In L. palustris the least variable of these simple ratios is L/W and the next best is L/l. Statistics are given for the distributions of these two ratios.

3. Data collected by Mozley are used to show that in L. palustris the ratio L/l (at least) is subject to considerable local variation, a fact which detracts from its value as a species constant.

Type
Research Article
Information
Journal of Helminthology , Volume 16 , Issue 4 , December 1938 , pp. 181 - 212
Copyright
Copyright © Cambridge University Press 1938

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References

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