THE CYCLOPHORID LAND MOLLUSKS OF AMERICA 147 



The following additional specimens are in the National Museum Col- 

 lection : No. 321006, from the Kedfield Collection ; No. 365365, 1 col- 

 lected by A. A. Hinkley at Chama, Alta Vera Paz, Guatemala; No. 

 32070, 2 collected by Sarg between Tactic and Tamaju, Alta Vera Paz, 

 Guatemala. 



This species is the largest of the smooth-whorled forms. In size 

 it resembles T. gealei Crosse and Fischer, and in sculpture it agrees 

 with the other species. 



TOMOCYCLUS COPANENSIS (Sowerby) 



Plate 19, Figure 3 



1850 Cyclostoma copanense Sowerby, Thesaurus conchyliorum, vol. 1, Suppl. 



p. 165*, pi. 31B, figs. 310, 311. 

 1886. Tomocyclus similacrum copanensis Fischer and Crosse, Mission scienti- 



fique au Mexique et dans TAm^rique centrale, vol. 2, pt. 7, p. 121, pi. 



40, figs. 4, 5, 7, 8, 10. 

 1886. Tomocyclus simulacrum var. d Fischer and Crosse, ibid., p. 121, pi. 40, 



fig. 6. 

 1890. Megalomastoma (Tomocyclus) simulacrum minus von Martens, Biologia 



Centrali-Americana, p. 10. 

 1890. Meglomastoma {Tomocyclus) simulacrum gracilius von Martens, idem. 



Shell small, chestnut-brown. The early whorls decollated in all 

 our specimens ; the latter well rounded, appressed at the summit, and 

 marked by lines of growth and indistinct spiral striations. Suture 

 well constricted. Periphery well rounded. Base moderately long, 

 with a strong keel marking the outer edge of the umbilicus, which 

 disappears on the last quarter of the last turn. Aperture circular; 

 peristome double, the inner slightly exserted; the outer fiaringly, 

 somewhat wavily expanded, with a slit on the parietal wall, which 

 communicates with the circular perforation a little behind the slit. 

 The two edges of the peristome are bent over to form a siphon. 



The specimen described and figured is one of two, U.S.N.M. No. 

 515763, collected by Godman at Coban, Guatemala. These diifer ma- 

 terially in size, so we are giving the dimensions of both. The speci- 

 men figured has 5.2 whorls remaining and measures : Height, 26 mm. ; 

 greater diameter, 12.6 mm. ; lesser diameter, 8.7 mm. Height of aper- 

 ture externally, 9.5 mm., internally, 5.8 mm.; diameter externally, 

 10 mm., internally, 5.5 mm. The smaller specimen has 5.5 whorls 

 remaining and measures: Height, 22 mm.; greater diameter, 10.8 

 mm. ; lesser diameter, 7 mm. Height of aperture externally, 8.3 mm., 

 internally, 5 mm.; diameter externally, 8 mm., internally, 5 mm. 

 The U. S. National Museum collections contain 3 additional lots : No. 

 316385, 3 specimens labeled "Guatemala"; No. 515764, 1 specimen 

 received from Sowerby & Fulton labeled "Guatemala"; No. 321005, 

 1 specimen from Alta Vera Paz, Guatemala, collected by Cuming. 



