ART. 4 



NEW UROCOPTID LAND SHELLS FROM MEXICO BAETSCH 



The type (Cat. No. 363131 U.S.N.M.) was collected by C. R. 

 Orcutt in river drift near Rio Balsas Station, Guerrero, Mexico. It 

 has 14 whorls, and measures — length, 10.9 mm. ; diameter, 4.6 mm. A 

 paratype (Cat. No. 363132 U.S.N.M.) has 16.7 whorls, and meas- 

 ures — length, 14 mm. ; diameter, 4.5 mm. 



HOLOSPIRA (COELOSTEMMA) ADANA, new species 



Plate 1, fig. 14 



Shell cylindro-conic, horn colored. Nuclear whorls 2.6, well 

 rounded, all but the last half marked by fine granules only. On the 

 latter there are slender retractively slanting axial riblets. Early 

 postnuclear whorls forming a narrow cone, well rounded, the middle 

 ones moderately rounded, marked b}^ numerous retractively slanting 

 aixal riblets which are a little more distantly spaced and a trifle 

 stronger on the cone than on the middle, but only a very little so. 

 On the last whorl they become very strong and distantly spaced. 

 Suture moderately constricted. Periphery well rounded. Base short, 

 rimate, strongly rounded, marked by the continuations of the axial 

 ribs which extend into the umbilical chink. Last whorl solute with 

 an obsolete angle at the posterior angle of the aperture and an even 

 less conspicuous one at the junction of the inner and parietal wall, 

 marked behind the peristome by closely spaced axial riblets which 

 extend all around the turn. Peristome expanded and somewhat re- 

 flected. The internal pillar rather stout, increasing in width poste- 

 riorly, hollow, marked by slender lines of growth and threadlike 

 axial riblets. 



The type (Cat. No. 363133 U.S.N.M.) was collected by C. R. Or- 

 cutt in river drift near Rio Balsas Station, Guerrero, Mexico. It has 

 17.8 whorls and measures — length, 19.1 mm.; diameter, 4.6 mm. 



Cat. No. 363134 U.S.N.M. contains 80 topotypes which yield the 

 following measurements : 



Greatest 



Least 



Average. 



Number 

 of whorls 



18.5 

 13.0 

 15.6 



Length 



20.5 

 13.9 

 17.1 



Diameter 



5.1 

 4.3 



4.8 



HOLOSPIRA (COELOSTEMMA) IQUALAENSIS. new species 



Plate 1, fig. 12 



Shell large, cylindroid, thin, semitranslucent, bluish white. 

 Nuclear whorls 2.8, strongly rounded, all but the last half of the 

 last one finely granulose, the axial rib sculpture of the postnuclear 

 turns encroaching upon the last half postnuclear turn, but the riblets 



