46 PEOCEEDINGS OF THE MALACOLOGICAL SOCIETY, 



to remarkable instances of convergence. Any future attempts to 

 investigate the taxonomy of this group as a whole must deal with a 

 large number of correlated characters, one of which should be the 

 structure discussed above. 



A fact of considerable interest for consideration under the first 

 part of this conclusion is the very remarkable similarity between the 

 longitudinal grooves found in the wall of the style-sac of Bythinella 

 and Paludestrina, and in certain Lamellibranch genera (Nelson,'^ 

 Edmondson ^). But the subject requires more investigation before 

 it can be properly utilized in this context. 



1 BoLivier, E., 1888, Mem. Soc. Phil. Paris (centenary volume). 



2 Bregenzer, A., 1916, Zool. Jahrb. (Anat.), xxxix, Hft. 2. 



^ Burne, R. H., 1920, Pelecypoda (Anatomy), Mollusca, pt. iv, British 

 Antarctic (" Terra Nova ") Expedition. 



* Collier, C, 1829, New Philos. Journal, vii. 

 5 Digby, L., 1900, Journ. Linn. Soc. (Zool.), xxviii. 

 « Edmondson, C. H., 1920, Journ. Exp. Zool., xxx. 

 ■^ Garnault, P., 1889, Actes Soc. Linn. Bordeaux, xli. 



8 Ghosh, E., 1920, Rec. Ind. Mus., xix, pt. i. 



9 Haller, B., 1888, Morph. Jahrb., xiv ; 1893, xix ; 1894, Studien iiber 

 Rhipidoglosse Prosobranchier, Leipzig 



" Huxley, T. H., 1853, Phil. Trans., vol. cxliii. 



11 von Ihering, H., 1885, Mai. Blatt., vii. 



12 Matthias, M., 1914, Jen. Zeitschr. Wiss., lii, pt. 3. 



13 Moore, J. E. S., 1898, Quart. Journ. Micr. Sci., xli ; 1899, ib. xlii. 

 1* Moquin-Tandon, A., 1855, Hist. Moll. France. 



15 Nelson, T. C, 1918, Journ. Morph., xxxi. 



1^ Pelseneer, P.. 1906, Lankester's Treatise on Zoology " Mollusca ". 



" Randies, W. B., 1902, Anat. Anz., xxi ; 1905, Quart. Journ. Micr. Sci., 

 xlviii. 



IS Robson, G. C, 1920, Ann. & Mag. Nat. Hist., ser. ix, vol. v; 1921, 

 ib. vol. viii ; 1922, Quart. Journ. Micr. Sci., Ixvi, pt. 1. 



" Simroth, H., 1901, Bronn's Thierreich (2nd ed.), Bd. 3. 



20 Try6n, W., 1887, Man. Conch., ix (under CeritUum aluco). 



21 Woodward, M. F., 1893, Proc. Mai. Soc, i ; 1-899, ib. iii. 



I 



