t86 The Hifiory ^ANIMALS, 
nua Ammonis, by tranfverfe plates or partitions, with a fiphuncle or little pipe run* 
ning through each : it is a rare fhell. r r 
I remember to have been it, fome years fince, in the river near Wifbech and alfo In 
fome parts of Leicefterfhire ; but, in the latter place, it was fmaller and lefs variegated. 
Ammonia fufca glahra ore deprejfo. 
The brown, fmooth Ammonia , with a deprejjed mouth . 
( This is about three quarters of an inch in diameter, and in the thickeft part is of the 
bignefs of a fmall goofe-quill; it confifts of about four volutions: the fhell is thin 
and eafily crufhed; the mouth is of a fomewhat depreffed form, the fecond volution 
of the fpiral entering a little way into it : the colour is a beautiful glofty brown, with¬ 
out any variegations, except that there run a kind of obfcure lines, fomewhat darker 
than the reft, marking the places of the divifions on the inftde of the fhell - thefe are 
formed of a thin, whitifh, fhelly matter, and ftand at about a line diftance from one 
another, dividing the cavity of the fhell in the manner of that of the nautilus. 
I have met with this in fome large ponds in Derbyfhire, and not elfewhere. 
Ammonia fubflavefcens minor glahra . 
The fmooth, little, yellowijh Ammonia. 
This is about a third of an inch in diameter, and in the largeft part is not thicker 
than a crow-quill: it confifts of about three volutions, terminating with a little um- 
do in the center : the whole furface of the fhell is perfectly fmooth and even, and it’s 
colour is a bright brown, with a conliderable tinge of yellow in it. 
We have this in fome of our fifh-ponds about London. 
Ammonia pallida coftata . 
The pale, ribbed Ammonia . 
This is about half an inch in diameter, and it’s largeft end is not much thicker than 
a crow-quill: the fhell is of a tender fubftance, and it’s colour very pale; it confifts 
of three or four volutions, and is all the way tranfverfely ribbed j the ribs are low 
and rounded, and mark the places where the plates are fttuated within, which form 
the divifions between the feveral cells. 
We have this, in great abundance, in the fen-ditches in Lincolnfhire. 
The other fpecies of the Ammonia are, i. The common, little brown Ammonia, 
2. The common, larger brown Ammonia, with a rim round the mouth. 3. The 
larger, white Ammonia. 4. The large, yellow Ammonia. 
FRESH-WATER SHELLS. 
Divifon the Second\ 
BIVALVE S. ' 
Thefe are much fewer in number than the fmple, or, as they are ufualiy 
called. Univalve Jhells', and more of the genera of the fea kinds are 
wholly unknown among them. 
C H A M m. 
Chama deprejfa Icevis albefcens . 
The white, fmooth, deprejfed Chama . 
npHis is about three quarters of an inch in breadth, and nearly of the fame 
X meafure from the hinge to the oppofite verge : the valves are both equally hol¬ 
lowed, but it is not much $ they are very thin, when joined, about the edge, and the 
gibbofity 
