The tliftory s/ANIMALS, 
The other fpecies of the Pholas, properly fo called, are, i. The fhort and very 
rough Pholas, of a greyifh colour. 2. The fhort, truncated Pholas, with deep fur- 
rovva. ^• The long ana fmooilier-fhelled Pholas. Authors have mentioned many 
other fpecies under, this name, but they are fhells of other genera, only called fo from 
their being found in hones. 3 
s H E L L-F I S H. 
Series the Second\ 
Thofe which inhabit the frejh waters. 
A MONG the Shell-fifti already defcribed as inhabitants of the feas, there are 
many fpecies that occafionally make their way up the larger rivers, and fome 
that will live in water which is only lalt while the tides flow : but there are a whole 
feries of others, which are truly and properly natives of the frefh waters only, and which 
die on being put into fea-water. Many of thefe are inhabitants of handing waters, as 
ponds and laices; others of our brooks and rivers; they are all referable to the genera 
of fea Sbell-fifh, and no formal diftindtion of them therefore will be neceflary here. 
The fyftem of this work would have pleaded for the joining them to the fea fpecies, as 
the place of living makes no regular diftindion ; but the cuftom of the prefent age, 
and the intent of rendering this part of natural hiftory as little confufed as poffible, 
have pleaded for the feparating thefe from the fea-fhells, and the land-fhells from thefe, 
but this only in place ; the generical names are continued from the former part of the 
work, and the fcientific reader has only to add thefe to the others, as fo many more 
fpecies. 
PATELLA, LIMPETS. 
Patella fubovata roftro elevato , incurvato. 
The fuboval Limpet , with an elevated and crooked roftrum . 
T H I S is a fhell of no great beauty : the generality of the frefh-water ones are, in¬ 
deed, in this refped, greatly inferior to thefe of the fea, but none more fo than 
thofe of this genus: this is a very thin fhell; the figure is oval, and deprelfed all over, ex¬ 
cept in the middle,where it rifes into a roftrum or beak; in other parts it is but very little 
elevated above the furface of the body to which it adheres: the roftrum is carried to a 
height equal to two thirds of the diameter of the fhell, and is fomewhat crooked and 
obtufe at the extremity : the whole fhell is little more than of the extent of a man’s 
finger-nail, and it’s colour is a dulky brown, with a tinge of olive ; it is very thin^ 
and eafily crufhed. 
We have it on ftones, in many of our brooks in Northamptonlhire. 
Patella elevata fubrotunda umbonata. 
The roundiflo , elevated , and umbonated Patella . 
• 
This is a fmaller fpecies than the former ; it rarely exceeds a third of an inch in dia¬ 
meter : it’s figure is roundifh, and it is confiderably elevated in a gibbofe manner, and, 
though not roftrated or beaked as the former, yet is terminated at the top by a round 
umbo or button, which gives that part a fingular appearance : it is a Very thin and de¬ 
licate fhell; it’s furface is tolerably fmooth, and it’s colour an olive brown, deeper on 
the outfide than within. 
It is found in fome of the rivers in Leicefterfhire: I remember to have met with It 
fticking to fmali pebbles, in a little brook that runs behind the houfe of Mr Caldecot, 
at Calthorp in that county; as alfo about Loughborough, and in fome other places. 
Patella. 
