NO. 1866 NEW SOUTH AMERICAN LAND SHELLS — DALL 363 



especially Buliinulus (Anctiis) aiigiostoiiius Wagner, and allied 

 forms. The surface soil, beside silica, contained nearly fifty per cent 

 of lime, over four per cent of carbonate of magnesia, and nearly nine 

 per cent of sodium chloride and sulphate. There is so much salt in 

 the soil that it is leached for the manufacture of common salt. Cer- 

 tain of the landshells, especially the Anctns, seemed to thrive best on 

 this salty ground ; after the pools of the rainy season had dried up, 

 they were noted upon the stems of weeds which grow abundantly 

 over this low ground. There were found a number of the shells of 

 Stropliochcilus oblongiis, variety crassits Albers, which had become 

 remarkably thickened internally ; some of the shell was about half an 

 inch thick, and the unbroken specimen felt as if it had been filled with 

 lead. Besides this species, Bulimiilns pachys Pilsbry and Odonto- 

 stonuis scctilabris Pfeiffer were identified, together with the follow- 

 ing new species. 



ODONTOSTOMUS (CYCLODONTINA) BRANNERI, new species 



Plate XXXVII, Figures 2, 3, 4 



. Shell slender, elongate, subacute, with nine and a half whorls sepa- 

 rated by a narrow, deep, but not channeled suture; nucleus small, 

 minutely punctate, with an apical dimple ; the subsequent sculpture 

 of fine, even, close-set retractive wrinkles, or riblets, extending from 

 suture to suture and over the base ; color white, with irregularly dis- 

 posed brown lines, usually distant and in harmony with the sculp- 

 ture ; whorls very slightly rounded, the last finally attenuated and 

 externally impressed over the internal denticles ; under the reflected 

 lip and behind the large lamina on the pillar is a minute umbilical 

 chink ; aperture with a strongly reflected white peristome, with a thin 

 layer of parietal callus, separated from the lip at either end by a 

 channel, shallow at the pillar-lip but deep at the external angle, 

 where it is bounded in front by a small lamina ; this sulcus, however, 

 is not indicated externally (as in O. scctilabris) by a marginating 

 band in front of the suture ; the armature of the aperture externally 

 visible resembles that of 0. scctilabris Pfeiffer, but, in harmony with 

 the whole aperture, is narrower, and the left hand basal tooth of 

 scctilabris is represented by two small but quite separate teeth ; an 

 examination of the internal armature shows that half a whorl behind 

 the large pillar-tooth the margin of the pillar is gyrate and swollen, 

 forming a lumpy callosity in the first half of the last whorl ; in 0. scc- 

 tilabris, however, the same part of the axis is slender, not gyrate or 

 swollen, but merely twisted like the axis in the whorls above. Length 



