312 DRYM^US, SOUTH AMERICAN. 



D. COLUMBIANUS (Lea). PL 45, fig. 33. 



Shell elongately turrited, perforate, shining, white ; thin ; trans- 

 versely and minutely striate ; apex golden color ; whorls 7 ; aper- 

 ture rather small ; outer lip acute. Length 1*2, diam. 0'5 inch. 

 (Lea). 



About 100 miles up the Magdalena River, Colombia (T. R. Peale)- 



Bulimus columbianus LEA, Trans. Amer. Philos. Soc., vi, p. 66, 

 pi. 23, f. 110 (1838) ; Obs. Genus Unio, etc., ii, p. 66, pi. 23, f. 110. 



The spire is long, and the aperture about one-third the length of 

 the shell. It is nearly milk-white, and so thin as to be somewhat 

 translucent (Lea). 



The type was in Peale's " Philadelphia Museum," and all trace 

 of it was lost upon the breaking up of the Museum in 1844. 



D. VENEZUELENSIS (Martens). PL 50, fig. 80. 



Shell somewhat fusiformly oblong, thin, hyaline ; compressly um- 

 bilicated. Whorls 7 in number, flatly convex, smooth, minutely 

 striated beneath the lens ; columella broadly reflected, depressed ; 

 aperture rather oblique ; lip simple, a little effused. Transparent 

 white (Eve.). 



Caracas, Venezuela (Moritz). 



Bulimus membranaceus Phil., REEVE, Conch. Icon., pi. 75, f. 

 544 (1849), not of Philippi. Otostomus (Mormus) membranaceus 

 MARTENS, Binnenmoll. Venez., p. 186, in Festschr. zur Feier des 

 100 Jahrigen Bestehens der Ges. Naturforsch. Freunde zu Berlin 

 (1873). Otostomus venzuelensis MARTENS, Biol. Centrali-Ameri- 

 cana, Moll. Terr., p. 224 (Sept., 1893), concealed in text relating to 

 Otostomus emeus. 



" Has the delicate, unicolored shell and fine, regular spiral stria- 

 tion in common with iirginalis audflavidus, but is larger and fatter 

 than either. Length 31, diam. four-ninths the length ; length of 

 aperture a very little more, but less than half. Larger and yellow 

 colored, but quite similar in form is Reeve's B. electrum, also from 

 Venezuela." (Martens, 1873). 



" The shell figured by Reeve as B. membranaceus is not Philippics 

 type ; it is probably similar to the Venezuelan specimens referred 

 by me to 0. membranaceus in the paper quoted above [Binnenmoll. 

 Venezuela's], and which may now be separated as a distinct species 

 under the name of Otostomus venezuelensis." (Martens, 1893). 



