NEW LAND AND FKESH-WATER MOLLUSKS FROM CEN- 

 TRAL AND SOUTH AMERICA 



By William B. Marshall 

 Assistant Curator, Division of MolJusks 



Eight of the eleven new species here described were received from 

 various correspondents during the last few months. The other three 

 were brought to light in revising the Museum collections. Two 

 of the species are from Central America, the others from South 

 America. 



ODONTOSTOMUS (CYCLGDGNTINA) CHASEAE, new species 



Plate 1, fig. 8 



Shell thin, slender, elongate; whorls eight and one-half, very 

 slightly rounded, subcrenulate along the sutures, which are impressed ; 

 sculpture consisting of many fine, flexuous, retractive lines of growth. 

 First four (nepionic) whorls corneous, the apical whorls regularly 

 grated like finely woven wire. Color yellow^ish white, with irregu- 

 larly placed, retractive streaks of chestnut, and a faint, narrow 

 white band on the periphery. Aperture about two-fifths the length 

 of the shell, its sides parallel to the axis, its basal portion nearly semi- 

 circular. Lip expanded throughout its course, being narrowly ex- 

 panded at the upper end of the outer lip, the expansion regularly 

 increasing from there to the upper end of the columellar lip, at 

 which point a minute portion is suddenly reflected toward the 

 umbilicus. Lip white, a brown band just within the aperture from 

 the upper corner of the outer lip to and including the lower edge of 

 the broad fold or tooth on the columella, and another brown stripe 

 farther within; and a faint spiral band within the aperture., 

 corresponding to the faint peripheral band on the exterior. Parietal 

 wall with a small callus at the end of the outer lip and another at 

 the end of the columellar lip ; a small, platelike tooth near the middle 

 of the parietal wall, a low tooth, or rather a swelling at the middle 

 point of the outer lip, another similar but slightly larger tooth near 

 the middle of the basal portion of the lip, and a strong, platelike^ 

 broad, twisted tooth near the upper end of the columella. Umbilicu.s^ 



No. 2638.— Proceedings U. S. National Museum, Vol. 69, Art. 12 



3097 — 26 1 



