520 MEMOIRS OF THE CARNEGIE MUSEUM. 



mcnts j2;ivcn by him belong to a specimen winch is exceptionally low. The measure- 

 ments given by Simjison for wymani do not belong to this species, but to apprimus 

 (See above, p. 513, footnote 18). 



I have a suspicion that D. felipponei Marshall (1917, p. 381, PI. 50, figs. 1-3, 

 PI. 51, fig. 1) from Maldonado and other places in Uruguay, is also this species. 

 The height as given is 70 to 72 i^r. ct. of the length, and the general shape and 

 otlier particulars agree, as for instance the hinge-teeth. But, according to the 

 figure, felipponei is less pointed behind, and the diameter is a little greater (40 to 

 46 pr. ct. The color also (yellowish-chestnut) is not exactly like lacteolus, which 

 has chestnut-olive-green tints. Thus I leave this question undecided. 



20. DiPLODON MOGYMiRiM Ortmann, sp. nov. 



Shells: PI. XXXVII, figs. 4, 5, 6, 7; Anatomy of gills: PL XLVI, fig. 5; Section of 

 gills: PL XLVIII, fig. 2; Glochidium: Text-fig. 4A-, p. 4(59. 



Type-locality. — Creek near Mogy Mirim, Sao Paulo, Brazil, tributary to Rio 

 Mogy Guassu and Rio Grande, upper Parana-drainage. J. D. Haseman coll., 

 August 28, 1908. Type-sct: Garn. Mus. Cat. No. 61.9260, fourteen specimens, males, 

 barren and gravid females, all with soft parts. (The original lot contained over 

 one hundred specimens.) 



Of all the species of Diplodon known from the upper Parana-drainage in Sao 

 Paulo only one described by Von Ihering resembles this in shape : Unio greeffeanus 

 (Von Ihering, 1893, p. 96, PL 4, fig. 8). However, the color of the epidermis of 

 the latter is described as being dark green to blackish, and this does not at all 

 fit our specimens, which are brownish black, without any distinct greenish tints. 

 Moreover, the dimensions given for the two specimens described by Von Ihering, 

 although falling within the range of variation of my specimens, are rather extreme, 

 and do not represent the normal condition of our species. The height is 61 and 

 64 pr. ct. of the length, while in my material this proportion varies from 62 to 74 

 pr. ct. ; and the diameter is 34 and 33 pr. ct., while it ranges, in my specimens, from 

 32 to 42 pr. ct. U. greeffeanus comes from the Piracicaba River (Campinas and 

 Piracicaba), while our specimens belong to the Rio Grande drainage. 



From the latter, and especially from Rio Mogy Guassu, at Jaboticabal (not 

 "Taboticabal" as printed), Simpson (1914, p. 1250) has described Diplodon trivialis. 

 Dimensions and description agree with our specimens to a degree; but again the 

 color is different, being described as black or dark brown, and tinted green, when 

 rubbed, while in our specimens, when rubbed (cleaned), the epidermis is of a i)eculiar 



