"""isw"'] PROCEEDINGS OF THE NATIONAL MUSEUM. 209 



whorls rather abruptly tapering towards the obtuse apex, which has a 

 slightly twisted and rather a papillose aspect. The last whorl is 

 curved under and constricted back of the mouth, forming- an umbilical 

 notch. The apex and following whorl are smooth ; the three or four 

 succeeding whorls sharply and somewliat obliquely plicated longitud- 

 inally, the median and following whorls becoming somewhat obscurely 

 sculptured other than by distinct growth- lines. The basal whorl is 

 strongly sculptured below, and back of the mouth, and obtusely 

 angulated underneath. Aperture ovate, slightly angulated anteriorly, 

 somewhat effuse, rimmed and projecting. The dimensions of two ex- 

 amples are as follows : 



Millimeters. 



Longitude 12^ 



Longitude 13 



Greatest diameter 4 



Greatest diameter : 4 



Habitat — Dos Cabezas, Arizona, w^here the above two specimens 

 and numerous fragments were found in a cave in November, 1889, by 

 V. Bailey, and contributed to the U, S. National Museum (No. 104392) 

 by Dr. 0. Hart Merriam. 



Among the species of this group that are geographically related is H, 

 Eemondi Gabb, described from Arivechi, Province of Sonora, Mexico, 

 a form sharply sculptured throughout, and in minor features also differ- 

 ent ; E. Pfeifferi Menke, collected by Remond at Hermosillo, in the same 

 province, with the previously named species; and H. {C (do centrum) 

 irregulare of Gabb from the high table-lands back of Mulege, in the 

 peninsula of Lower California. All of these are separable at a glance 

 from arizonends. 



M. M. Fischer and Crosse, in the " Mission Scientiflque au Mexique 

 et dans I'Amerique Central,"* point out the geographical as well as 

 conchological and jnalacologic relations and characteristics of the group 

 Holospira, and furnish a resume of the species thus fart made known. 

 Their distribution geographically considered is decidedly Mexican and 

 semitropical, and the relations of the shells when the shell characters 

 are considered, as well as certain of the anatomical details, indicate a 

 closer affinity with the Pupidw than with the CylindrcUae. That there 

 should be what we may be permitted to call outlying posts, and areas 

 exterior to the territory of Mexico, where this general form is repre- 

 sented, may reasonably be expected, for the distribution of life is gov- 

 erned by physical conditions, not by political lines. Quoting from the 

 authorities above cited, we find the number of species in this group up 

 to the date of the foregoing publication to be thirteen^ supposing the 

 sp'ecies described to be valid and not synonymous. The names and dis- 

 tribution of these is as follows : 



(1) H. Pfeifferi Menke, Tehuacan, in the province of Puebla, and 

 variety (yS, C. and P.) Hermosillo, in the ])rovince of Sonora. 



* Septierae partie. 1 1873. 



Proc. N. M. 90 14 



