304 



1930 Aplexa rivalis rivalis Mat. and Rack., Baker, H. B., 

 Occas. Papers Mus. of Zool. Univ. Michigan 210, p. 36. 



An examination of several lots of Physa, distributed by local 

 collectors as P. heterostropha acuta Drap. from southern Cali- 

 fornia agree in description and figure with P. osculans Hald. 

 described from Mexico. The name P. fontinalis acuta (Drap.) 

 was first used by Hannibal (1912, p. 164) in an all inclusive 

 synonymic grouping of the American Physidae. 



The name P. heterostropha acuta appeared later as a modifica- 

 tion of Hannibal's grouping. Hannibal's work has no basis of 

 fact upon which to stand. 



Haldeman first pubhshed P. osculans (1843, p. 29, pi. 2, fig. 

 11-13) with three figures. His figure 13, in the original diagnosis 

 was said to probably be another species. Binney (1865, p. 83) 

 in .error, considering Haldeman's figures 11 and 12 to be P. 

 heterostropha, assigned figure 13 to osculans. Fischer and Crosse 

 (1886, p. 101) likewise noted the discrepancy in Haldeman's 

 figures, assigning a new name for figure 11 (conoidea), limiting 

 P. osculans to figure 12, but putting it in the synonymy of P. 

 mexicana Phil, and definitely assigning figure 13 to the genus 

 Aplexa, the species probably being A. nitens Phil. 



A careful comparison of figures bears out these contentions 

 that Haldeman's figure 13 is Aplexa nitens, but in regard to 

 P. osculans, this name has priority of two years over that of 

 P. mexicana Phil. Pilsbry (1891, p. 323) pointed out that P. 

 houcardi C. and F. is also a synonym of P. osculans. The follow- 

 ing is a resume of the above, using Haldeman's plate figures for 

 the final assortment of forms. 



Physa osculans Haldeman. 



1843 Physa osculans Haldeman, Mono. Limniades, pt. 6, p. 



29, pi. 2, fig. 12. 

 1845 Physa mexicana Phil., Conch. Cab., vol. 1, pt. 17, p. 5, 



pi. 1, fig. 3-4. 

 1881 Physa houcardi C. and F., Journ. de Conch., vol. 29, p. 



334; Miss. Sci. Mex., Moll. vol. 2, p. 102, pi. 30, fig. 



4-4a. 



