420 The American Naturalist. [May, 
the earth carry down the molecules of lime in a ceaseless cur- 
rent with the common sea, where says Dana " after circulating 
over thousands of miles and for unknown times, they are 
brought to light and rendered tangible again by the incessant 
labors of millions of minute living gelatinous bodies, and by 
these insignificant organisms the lime is built up again into 
masses almost rivalling the original in dimensions and impor- 
tance, but losing in this, its new dress, all traces of its divine 
origin and divine age." Thus he says, "we may have rocks 
from the snow-covered summits of the Himalayas, the lime- 
stones of the burning plains of India, and the strata of inac- 
cessible China, removed from their respective districts — into 
the great common receptacle." 
Modern science teaches that the small has produced the 
great, that the earth as we now know it has been fashioned by 
forces which are in operation to-day. The small indeed may 
be the most significant, and size in the vocabulary of biology 
at least may be an unimportant term. 
SOLENISCUS: ITS GENERIC CHARACTERS AND 
RELATIONS. 
yHE genus Soleniscus was established by Meek and Worth- 
en to include gastropod shells closely allied to the 
widely known Macrocheilus ; and said to be distinguished 
from the latter chiefly by the presence of a single elevated fold 
on the columella and by being produced anteriorly into a short 
canal. The authors described under this genus but a single 
species — 5. typicus. Miller,' however, in 1877, included also 
Macrocheilus hallanus Geinitz. Four years later White' de- 
scribed from New Mexico 5. planus and S. brevis ; and after- 
wards" referred to the genus five other species which had orig- 
, Supp. t 
