41 
Nos. 1 — 8 contain the Brachiuri, or short- room ix. 
tailed Crustacea, of which Nos. 1—5 are Crabs. 
Amongst these are specimens of the Swimming 
Crabs, of the genera Polybius, Portunus, Po- 
dophthalmus, &c. These animals have the pos¬ 
terior leg terminated by very flat joints, of an 
oval or orbicular form, and calculated to act as 
fins in swimming. The last pair of legs in all 
the Swimming Crabs, are constantly furnished 
with these flattened joints, and in some species 
the preceding pairs have them also, but never 
so broad as those of the hind legs. The eyes 
of the Telescope Crab (Podoplithalmas spinosus ), 
are supported on very long slender pedicles, 
reaching from the middle of the anterior margin 
of the shell to the lateral angles, and lodged, 
when at rest, in a groove on the edge. This is 
the only known recent species belonging to this 
genus. Here are also specimens of the Thel- 
phusae, or Fresh-water Crabs, which live in the 
rivers and streams of Italy, and the south of 
Europe, and are also found in Asia and Ame¬ 
rica : they are capable also of existing a con¬ 
siderable time out of the water. One species, 
peculiar to the south of Europe and the Levant, 
(.Le Cancre de riviere of Rondeletius,) enjoyed 
great celebrity amongst the Greeks, for its 
supposed medicinal virtues, and is frequently 
represented on the coins of Agrigentum, with 
the 
