778 PROCEEDINGS OF THE ACADEMY OF [DcC, 



Physa osculans patzcuarensis Pils. 



Proc. Acad. Xat, Sd. Pliila., 1891, p. 323, PL XV, fig. 5. 

 Physa me.xirana var. coniformls Strebel, Tieitrag I, -p. 52 (1S73), Xot Physa 

 coniformis Tryon (1866). 



Lake Patzciiaro (Rhoads, 1S99). Numerous specimens were taken 

 like the types collected by Hcilprin. At the time I described the latter 

 I Avas not aware of the previous description of the same form by 

 Strebel. He used a preoccupied name which laid in aml^ush in a dense 

 thicket of text. 

 Physa berendti Dkr. 



Texolo and near Jalapa, State of Vera Cruz. 



Physa lacustris Clessin. 



At Texolo, State of Vera Cruz, in a small stagnant pond, and under a 

 cascade, a very short -spired Physa occurred which seems identical with 

 Clessin's species. The specimens from the small pond reach a length 

 of 10 mm., and are much eroded, having lost most of the cuticle. 

 Those from under the cascade are 6 to 1h mm. long, and more globose. 

 It seems to be a well-marked species. 



Clessin gives ''Centralamcrika, See Coatcpeque," as the locality. 

 There is a Coatepeque in western Guatemala; but Dr. von ]\Iartens says 

 "E. Mexico: Lake Coatepec," probably the correct locality. 



VALVATID.^. 

 Valvata humeralis Say. PI. LIT, figs. 9, 12, 12a. 



T'. humeralis Say, X. H. Diss., II, 244, Martens, Biologia Cent. Amer., 



Moll., p. 426. 

 V. humeralis Say {humerosa Say), Strebel, Beitrag I, p. 33, PI. 4, fig. 42 (not 



good). 

 V. strebeli Crosse and Fischer, Miss. Scient. au Mex., Moll., II, p. 304 (based 



upon preceding reference) . 



Say's tj^pe specimen is here drawn (figs. 12, 12fl). It agrees with 

 specimens before me from the city of Mexico (Heilprin expedition), 

 and from Lake Xochimilco (fig. 9) in the valley of Mexico^ (E. D. Cope, 

 1SS5). The figures given by Strebel show a raised, acute apex, but as 

 he expressly states that the apex is obtuse, I suppose these figures to 

 be incorrectly drawn. It may be added that Strebel's description 

 agrees fully with some specimens of V. humeralis. This being the case 

 V. strebeli C. and F., based solely upon Strebel's account, will become a 

 pure synonym of V. humeralis. Prof. v. ^Martens has already treated 

 it as a variety of that species. It may further be noted that jMessrs. 

 Crosse and Fischer had seen neither V. humeralis nor the form they 



' Lake Xochimilco is tlie west end of I-ake Clialco, from wliicli it has been 

 artificially separated. 



