HOLOSPIRA, SUBG. COELOSTEMMA. 99 



entire breaking up of the vertical riblets, as in some forms of 

 the genus mentioned. Only three species are known. 



H. elizabethce: Shell cylindric or club-shaped, white or 

 whitish, widest above, the internal column of the same shape, 

 and nearly half the diameter of the shell. 



H. dalli: Shell barrel-shaped, dotted or necked, widest below 

 the middle, the internal column similarly shaped, half the 

 diameter of the shell. 



H. strebeliana: Shell cylindric, very blunt at the ends, 

 dotted, the internal column cylindric and one-third the diam- 

 eter of the shell. 



H. microstoma (species no. 25) and H. imbricata (sp. no. 

 26) may belong to this subgenus, but their internal charac- 

 ters are undescribed. 



22. H. ELIZABETHAE Pilsbry. PI. 15, figs. 6-15 ; pi. 26, fig. 27. 



Shell rimate (rarely perforate), cylindrical or club-shaped; 

 usually being wider and sometimes swollen above, terminating 

 in a short cone; white or fleshy- white, the apical whorls gen- 

 erally blackish; moderately solid. Whorls varying from 17 

 in short to 21 in long individuals, closely coiled and but 

 slightly convex, the sutures slightly impressed, but sometimes 

 emphasized by the slight angular projection of some whorls 

 over those following. Earliest 2 whorls smooth (the first 

 larger) , following 5 or 6 whorls of the cone closely and finely 

 striate; subsequent whorls nearly smooth except the last, 

 which has distinct riblets much narrower than their intervals. 

 Last whorl rounded below, flattened above, somewhat pro- 

 duced forward. Aperture rounded, the upper margin 

 straightened, peristome expanded, thin. Interior pale ochre 

 tinted. Internal column large, wider above; white, slightly 

 contracted and smooth at the base within each whorl, else- 

 where irregularly ribbed, the ribs narrow, oblique and acute, 

 wanting within the whorls of the terminal cone. 



Length 21.6, greatest diam. (above) 6, diam. of penult, 

 whorl 5 mm. ; whorls 21. 



Length 17, greatest diam. (above) 6, diam. of penult, whorl 

 5 mm.; whorls 17%. 



