THREE NEW LAND SHELLS FROM MEXICO 



By Paul Bartsch 



Curator, Division of MollusJcs, United States National Museum 



In a recent sending of land mollusks from Mexico, received from 

 C. R. Orcutt, are three new Urocoptid land shells, which are here 

 described. 



HOLOSPIRA (HOLOSPIRA) ORCUTTI, new species 



Plate 1, figs. 5, 6 



Shell large, cyhndro-conic, flesh colored with a pinkish flush. 

 The last half of the last turn jnarked mth pale-brown, which is also 

 the color of the base. Nuclear whorls 2.3, large, strongly rounded, 

 smooth, forming an almost mammillate apex. Early postnuclear 

 whorls increasing rapidly m size, marked by rather strongly decidedly 

 retractively slanting threadlike riblets which are separated by spaces 

 three and four times the width of the riblets. These riblets become 

 evanescent on the sixth turn and on the whorls that follow there are 

 mere indications of them. The last turn and a half is again ribbed 

 and on the latter portion of the last whorl the riblets are almost 

 lamellar. The early whorls are slightly over-hanging, while the rest 

 are appressed at the summit. About one-tenth of the last turn is 

 free at the summit, and the angle of the summit stands out markedly 

 here. There is a subobsolete constriction where the side of the 

 whorl meets the basal portion, the axial ribs extending over the base 

 into the umbilical region. The umbilicus is rimate, but not open. 



Aperture rather large with a very broad, thick, slightlj^- reflected, 

 wide, shining peristome. Interior of aperture pale-brown. 



The type, Cat. No. 361960, U.S.N.M., has 14.5 whorls and measures: 

 Altitude, 25.3 mm.; greater diameter, 8.4 mm. It was collected on 

 a limestone paredon at Coahuila, Mexico. 



No. 2594.— Proceedings U. S. National Museum. Vol. 67, Art. 22, 



54205— 25t 1 



