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X. Défcription of the Cancer flagnalis of Linneus, by George Shaw, 
M. D. F. R.S. Fellow of the Linnean Society. 
Read Fanuary 6, 1789. 
HE Cancer ftagnalis of Linnæus being certainly one of the 
moft curious animals of the genus to which it belongs, and 
being not yet fo generally known as the reft of the Britifh fpecies ; 
I hope the following obfervations, which I have had frequent op- 
portunities of making on this infeét, and particularly thofe which 
relate to its infant ftate, or firft appearance from the egg, may be not 
unacceptable to the Linnean Society. 
The Cancer ftagnalis is generally found in fuch waters as are of 
a foft nature, and particularly in thofe fmall fhallows of rain-water 
which are fo frequently feen in the fpring and autumn, and in 
which the Monoculus Pulex of Linnzus, and other fmaller animal- 
cula abound. At firft view this infect bears fome refemblance to 
the infeét which fome writers have called Squilla aquatica, or the 
larva of a Dytifcus; but when viewed nearly it is found to be of a 
much more curious and elegant appearance thanthat animal. The 
legs, of which there are feveral pair (eleven) on each fide, are flat 
and filmy, and have the appearance of fo many waving fins, of the 
moft delicate ftruéture imaginable. The whole animal is ey 
trani- 
