THE SMALLER SHA-SHELLS 205 
From these two large shells we bound back to 
some very small ones most of which, in fact are 
so minute, that no attempt will be made to describe 
them in this book. Fortunately it is not necessary, 
for a work is shortly to be published by the Na- 
tional Museum, we are told, which will fully de- 
scribe the great group of minute shells known un- 
der the generic name of T'urbonilla. 
The general shape of these little shells 
is shown in Figure 217, and the species 
indicated by that cut is known as T'ur- 
bonilla castanea, Cpr., the Chestnut Tur- 
bonilla, (Chemnitzia castanea). Its eight 
or ten whorls are marked with numerous 
fine axial ribs, and though it is so small it is a 
beautiful shell. Its color is chestnut brown, as 
might be expected from its name. 
The Odostomias have white shells, less slender 
than those of the last genus. On the columella is 
a fold like a tooth as their name indicates. There 
are a good many species, most of which 
i are very small. One of the largest shells 
is shown in Figure 218. It is known as 
Odostémia pupiformis, Cpr., the Pupa- 
shaped Odostomia, (O. satura). This shell 
is beautifully white, not very thick, with deep su- 
tures and a microscopic network of extremely fine 
lines. It is about a quarter of an inch in length. 
This species ranges along the whole coast. 
Odostémia nuciformis, Cpr., the Nut-shaped 
Fig. 218 
