188 
The Hiftory of ANIMALS. 
Mytulus fafciatus albefcens variegatus. 
The whitijh , variegated , fafciated Mytulus ♦ 
This fpecies alfo approaches to the figure of the teliina of authors: it is about ail 
inch in meafure from the extremities of the Tides, but is not much more than half an 
inch, from the hinge to the oppofite verge of the fhell: it’s colour is whitifh, varie¬ 
gated with biown j the valves are both confiderably gibbofe, and the furface is pretty 
deeply fafciated. r y 
We have this in mod; of our large rivers. 
Mytulus angulatus anguflior fufcus. 
The narrow y brown , angulated Mytulus . 
This is near an inch long, and not half an inch in breadth 5 the valves are both 
very deep, fo that it’s thicknefs is nearly equal to it’s breadth : they are not even on 
the furface, but are irregularly angulated, and raifed into two or three ridges j the fub- 
fiance of the fhell is tolerably thick and flrong 5 the colour a pale brown, with a tinge 
of the olive. 
We have it in fome of our ponds, but it is not common. 
The other fpecies of the frefb-water Mytulus are, i. The little, purplifh, thin My¬ 
tulus. 2. The white, oblong, fmooth Mytulus. 3. The brown, oblong, fmooth 
Mytulus. 4. The broad and flat, flightly fafciated Mytulus. 5. The pale red, thin, 
firiated Mytulus. 6. The larger, dufky greyifh Mytulus. 7. The large, brown* 
thick Mytulus. 8. The great, broad, fmooth, brown Mytulus, pearly within, called 
the Horfe-mufcle, or the Pond-mufcle. 9. The greater, oblong, brown Mytulus, 
pearly within. 10. The large, yellowifh, fmooth Mytulus, pearly within. Thefe 
three lafl are common in our ponds, and are by many indiferiminately called the Horfe- 
mufcle. 
CARDIN, HEART-SHELLS. 
Cardia prof wide Jlriata triangularis . 
The tria?tgular^ deeply Jlriated Cardia . 
T HIS fpecies has fome refemblance to the common cockle eaten at our tables, 
but more to fome of the foffile Conchas Anomias: it is about half an inch broad* 
and nearly as much in length, from the hinge to the extream verge ; it is broad at the 
bottom, whence it grows fmaller to the top where the hinge is, and, though 
rounded at the verge, it by this means approaches to a triangular figure: the whole 
furface is deeply firiated or furrowed ; the ridges between the furrows are narrow and 
rounded, and the colour is a pale brownifh, almofl white, with a faint tinge of red- 
difh in it. 
We have this in confiderable abundance in fome of our large rivers, 
Cardia fubglobofa livida. 
The bluifb , rounded Cardia , 
This is an elegant fhell, and, when viewed tideways, has as much the appearance of 
the figure of a heart at cards, as any of the marine kinds: it is about an inch in length, 
and is as much in diameter from fide to fide, and but little lefs in thicknefs: the whole 
furface is elegantly, but not very deeply, firiated, and the colour is a livid or dufkv 
bluifh. 
I met with a few fpecimens of this in the river Nen, near Water Newton in 
Northamptonfhire; elfewhere I have not feen it. 
Cardia fafciata fubrubens . 
The reddijh , fafciated Cardia . 
This is alfo an elegant fhell for one of the frefh-water kind j it is about half an 
nch in length, from the hinge to the oppofite verge, and is nearly as much in dia¬ 
meter : 
