216 PROCEEDINGS OF THE ACADEMY OF [Mch., 



intervals or a little narrower, except on the last whorl, where the sculp- 

 ture is a little coarser and irregular. The whorls are all convex, the 

 last 4 or 5 forming the cylindric portion, the preceding whorls forming 

 the terminal cone, which is about one-third the total length of the shell. 

 The last whorl is pinched or compressed laterally, but the very short 

 straight "neck" is full again, and carries the aperture very shortly 

 free. The aperture is rounded, but a little irregular, the upper margin 

 being somewhat straightened. The thin peristome is narrowly ex- 

 panded. 



The internal pillar is rather large and of ec^ual calibre in the cylindric 

 portion of the shell. At the end of the penultimate and beginning of 

 the last whorl there is a short strong and blunt lamella on the pillar 

 below the middle, a low, short lamella on the parietal wall and another 

 on the basal wall. There is no palatal lamella. 



Length 7.5 to 9, diam. 3 mm. 



Manilla mine, Huachuca Mountains. 



This is a very short, thick-set species, unlike all others known in its 

 internal armature. The even ribbing and short terminal cone are also 

 characteristic. It is closely related to H. arizonensis Stearns, from 

 Dos Cabezas, a place west of the Chiricahua range and not far from one 

 of the localities of H. ferrissi; but besides the slight difference in inter- 

 nal structure, H. arizonensis differs in being slightly larger with more 

 whorls, and the riblets are subobsolete on the cylindric portion of the 

 shell, while in H. ferrissi they are even stronger there than on the ter- 

 minal cone. 



This species occurred also at Fort Bowie, Arizona, where the shells 

 average a trifle larger : 



Length 7.5, diam. 3 mm., whorls 9^. 



Length 10, diam. 3 mm., whorls IH. 



This species seems to partially connect typical Holospira with the 

 sections Eudistemma and Distomospir'a . The lamellse are far shorter 

 and weaker than in the typical section, in fact, might easily be over- 

 looked. 



Holospira arizonensis Stearns. 



This shell is cylindric wdth a short, ribbed, terminal cone. The median 

 whorls are smoother, only obscurely sculptured, and the last whorl is 

 ribbed. Whorls 12 or 13. 



The internal axis is moderately large, and there is a short lamella on 

 the axis and one on the parietal wall or roof in the penultimate whorl. 



Lengtl\12.5 to 13, diam. 4 mm. 



Southeast Arizona, at Dos Cabezas, Cochise county. 



