THE CYCLOPHORIT) LAND MOLLUSKS OF AMERICA 145 



TOMOCYCLUS SIPHONIS. new species 

 Plate 19, Fiiqube 5 



Shell of medium size, olivaceous with a chestnut tinge; peristome 

 bluish white, which is also the color of the interior. Early whorls 

 decollated in all our specimens; those remaining well rounded, ap- 

 pressed at the summit, which is slightly denticulated and marked by 

 lines of growth, which do not form riblets. There is also an indi- 

 cation of microscopic spiral striations. Suture strongly constricted. 

 Periphery well rounded. Base with a weak carina at the outer edge 

 of the umbilicus, which disappears on the last quarter of the last turn. 

 Aperture circular; peristome double, the inner moderately exserted; 

 the outer broadly flaringly expanded and somewhat wavy with a 

 strong sinus on the middle of the parietal wall, which connects with 

 a round opening, over which the two sides of the reflected outer 

 peristome form a pseudosiphon. Operculum typically tomocyclid. 



The type, U.S.N.M. No. 162511, was collected by von Ihering at 

 Alta Vera Paz, Guatemala. It has 5 whorls remaining and measures : 

 Height, 31 mm. ; greater diameter, 14.6 mm. ; lesser diameter, 9.7 mm. 

 Height of aperture, 12.9 mm. externally, 5.9 mm. internally ; diameter, 

 12.2 mm. externally, 5.8 mm. internally. 



This differs from T. constrictus in having the pseudosiphon much 

 more strongly developed and the basal carina much weaker ; it is also 

 paler in coloration. 



TOMOCYCLUS CONSTRICTUS, new species 

 PI4ATE 19, FiGUEE 2 



Shell of medium size, elongate-turrited, covered with a chestnut- 

 brown periostracum. Early whorls decollated in all our specimens; 

 those remaining strongly rounded, slightly denticulated at the sum- 

 mit, and marked by feeble obsolete axial riblets corresponding to the 

 denticulations at the summit; these, however, evanesce on the major 

 portion of the base. In addition to this, the whorls are marked by 

 fine spiral striations. Suture strongly constricted. Periphery well 

 rounded. Base slightly produced, bearing a very strong keel at the 

 outer limit of the umbilicus. Aperture circular; peristome double, 

 the inner moderately exserted; the outer broadly, wavily, flaringly 

 expanded, with a notch in the parietal wall which connects with the 

 round opening. The two sides of the peristome arch over to partly 

 cover the pseudosiphon. Operculum typically tomocyclid. 



The type, U.S.N.M. No. 162315, was collected by Godman at Coban, 

 northern Guatemala. It has 5.3 whorls remaining and measures: 

 Height, 32.8 mm.; greater diameter, 15.2 mm.; lesser diameter, 10.4 

 mm. Height of aperture, 12.6 mm. externally, 6.5 mm. internally; 

 diameter, 12.2 mm. externally, 6.3 mm. internally. 



