82 



CALIFORNIA ACADEMY OF SCIENCES. 



number of nominal species will bear still further reduc- 

 tion, and that more study of different ages and variations 

 will alone prove which are the leading types. 



Following Prime's suggestion, it is desirable to give a 

 name to the calyculate group, and certainly none can be 

 more appropriate than Primella, which perpetuates the 

 memory of the most thorough student of the genus. It is 

 possible that it may even supersede that of SpJK^rium, as 

 the genus Spheria among Fungi has nine years priority. 



Ancylus caurinus W. Cooper, subsp. subalpinus. 

 Apex about one-third the distance from posterior end, 

 outline elliptic, sometimes widest at middle, sometimes 

 about anterior third, apex slightly turned to the right; 

 anterior surface somewhat convex, posterior a little con- 

 cave or flat; breadth a little under one-half, height over 

 one-third of length; fragile, horn -color, paler in thin 

 specimens. 



Figure. Length. Breadth. Height. 



Original type 0.24 0.14 0.09 caurinus. 



Oregon example 26 0.21 0.13 0.07 .subalpinus. 



Yoseraite example 27 0.23 0.12 0.07 subalpinus. 



Bloody Canon example .... 28 0.21 0.13 0.07 subalpinus 



San Francisco, type 0.16 0.04'/; 0.04 fragilis. 



E. of San Francisco Bay . ... 29 o.ii 0.07 0.04 fragilis. 



The original A. caurinus was named in the report of 

 Pac. R. R. Surveys, XII, ii, 1859 (Natural Hist, of Wash. 

 Ter.), and a type figured by W. G. Binney in Land and 

 Fresh-Water Shells, Part II, p. 144, 1865, without de- 

 scription. In 1870, I published the description in our 

 Proceedings, Vol. IV, p. 92, from which the above is 

 copied with some changes, so as to include the Oregon 

 and subalpine specimens. The dimensions of the type 

 are given more accurately from Binney' s figure, and 

 those of the others as figured, from the examples them- 

 selves. It thus appears that the Oregon and subalpine 

 forms are nearly of the same form as the original from 



