116 ZOOLOGY. 
the sixth. These Crustacea, although they walk well, must be regarded as 
chiefly swimmers, shooting backwards through the water by the action of 
the abdomen and caudal fin. 
fram. 1. Scyllaride (cuirassés, M. Edwards). In the genus Palinurus 
pl. 78, fig. 11) the body has much the shape of that of a lobster, but is 
more cylindrical, and none of the feet are cheliform, although the anterior 
ones are rather more robust than the others. The carapace is armed 
anteriorly with two large spines; the external antenne are very long, with 
the base spiny; the basal segment of the abdomen is without false feet, 
although the four following have them. The species are of a large size ; 
they have a very hard shell, and they live upon rocky coasts. The European 
species, P. vulgaris, attains a length of fifty centimetres, and a weight of 
eight kilograms. It is the karabos of Aristotle, and the docusta of Suetonius 
and Belon. The various species are more or less spinous. Scyllarus (pl. 
78, fig. 12) is remarkable for having the peduncle of the exterior antennz 
much dilated laterally, and more or less dentated, the terminal filaments being 
absent. The sub-families are: Galathenw, EHryonine, Scyllarine, and 
Palinurine. | | 
fram. 2. Astacude. This family includes the genus Astacus (lobster) and 
Potamobia, the analogous fresh water form known under the English names 
of crawfish, crayfish, crevish, or crevis, the three last of which agree in the 
first syllable. The latter are caught in Kurope for food, by placing decaying 
meat in nets or bunches of brushwood, from which they cannot readily 
escape. They are also caught by a bait at the end of a stick, which they 
will not leave if it is withdrawn slowly, until a net can be passed under 
them. They are said to live twenty years, and to grow during this period. 
The genus is well represented in the United States. Callcanassa (pl. 78, 
fig. 14). C. major, of Say, is four inches and a half long, and was found 
by this author “ by digging in the sand of the bay shore of the river St. 
John, in East Florida, about eighteen inches below the surface, near low- 
water mark; it had formed a tubular domicil, which penetrated the sand in 
a perpendicular direction to a considerable depth; the sides were of a more 
compact consistence than the surrounding sand, projecting above the surface 
half an inch or more, resembling a small chimney, and rather suddenly 
contracted at the top into a small orifice.” The second family, fouwesseurs of 
Milne Edwards, is included in the Astacede by Latreille. The sub-families 
are: Glaucothoine, Callianidine, and Astacine. 
Fam. 3. Palemonide. Palemon, which is much used for food, inhabits 
sandy bottoms near the coasts, or the mouths of rivers, and like the lobsters, 
boiling turns them red. Stenopus (pl. 78, jig. 13, exhibiting the false feet 
under the abdomen). The sub-families are: Crangoninw, Alphema, 
Palemonine, and Penwina. 
Fam. 4. Mysiside.* Some authors place this family with the se aprey 
It includes two sub-families: Mysisine and Leuciferine. 
* Under a different form this name might be supposed to be derived from Mysia or Mysidia, 
instead of Mysis. 
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