298 



PROCEEDINGS OF THE ACADEMY OF [NoV.-DeC, 



As the error in measuring may be at least 0.1 mm., it will be seen, 

 if a curve is plotted, that the mode for diameter is at about 24.4 mm., 

 and the total variation 2.1 mm. in either direction. 



A specimen having the umbilicus exceptionally narrow is illustrated 

 in pi. 4, figs. 8-86. The spire is also narrower than in the typical 

 form; yet it seems unlikely that there is more than one species in the lot. 



Sonorella galiurensis n. sp. PI. V, figs. 5 to 66. 



The shell is umbihcate (the width of umbilicus contained about 

 9 times in that of the shell), between cinnamon-brown and sayal- 

 brown in color, fading on the base, and much paler on both sides of 

 the broad chestnut-brown band above the periphery. Glossj^; em- 

 bryonic whorls closely pitted-granulate, with the usual protractive 

 threads; subsequent whorls lightlj^ marked with irregular growth- 

 lines. The last whorl is wide and descends somewhat in front. The 

 peristome is narrowly expanded. The parietal callus usually has a 

 thickened edge in fully adult shells. 

 Alt. 16.7, diam. 27.5 mm.; 5 whorls, (type, Sta. 30). 

 " 16, " 21 A " 5 " (Sta. 30). 

 " 16.4, " 25 " 5 " (Sta. 30). 

 " 16.7 '' 30.5 " 5 " (Sta. 34). 

 Galiuro Mountains at the following Stations (1917): 



Fig. 7. Genitalia of Sonorella galiurensis, No. 118,122. 



