DECAPODA. 
207 
Sometimes the superior antennae liave three threads. 
They have four didactyle claws, the smallest of which are folded 
up, and an elongated rostrum. 
Pal.emon, Fah. 
Prawns are distinguished from the two following subgenera by 
their inarticulated carpus ; the second feet are larger than the first ; 
the latter are doubled up. A remarkably large species is found in 
the East Indies, the second claws of Avhich are very long. Tolerably 
large ones are also found at the Antilles, some of whicli frequent the 
mouths of rivers. Those on the coast of France are much smaller, 
and are known there by the vidgar names of Crevettes and Salicoques. 
Their flesh is more highly esteemed than that of the Slirimp. Ac- 
cording to M. de Brebisson — Catal. Method, des Crust, terrest. et 
fluviat.,du Depart, du Calvados, — they are taken in the same manner 
as the latter Crustacea, but in the summer only. Prawns swim well, 
particularly when escaping from pursuit, and in various directions. 
They are always found about the shore. The lithographic stone of 
Pappenheim and Solhnofen frequently exhibits the debris of a fossil 
crustaceous animal, referred by Desmarest to the Prawns, under 
the specific appellation oi spinipes — Hist. Nat. des Crust. Foss. XI, 4. 
It does in fact resemble it, but the claws are Avanting. A second 
fossil species, but much larger, has been discovered in England. 
Pal. serratus, Leach, Malac. Brit. XLIII, 1, 10; Herhst,, 
XXVH, 1, is from four to five inches long, of a pale red colour, 
which becomes more vivid on the antennae, the posterior margin 
of the segments of the tail, and particularly on the terminal fin. 
The rostrum extends beyond the peduncle of the intermediate 
antennae, is recurved at its extremity, and has five teeth above, 
exclusive of the jioint, and five beneath. The fingers are as long 
as the penultimate joint. It is found on the coast of France and 
England, and is the species of this subgenus that is more particu- 
larly sold at Paris. A sort of wen is frequently, and at all sea- 
sons, observed on one side of the shell, Avhich covers a parasite 
Bopyrus, which fastens upon its branchiae. 
Pal. squilla, Leach, Malac. Brit., XLIII, 11 — 13; Cancer 
squilla, L. ; Squilla fusca, Bast., Opusc. subs., lib. 2, 111, 5, is 
but half the size of the serratus. Its rostrum scarcely extends 
beyond the peduncle of the superior antennae, is almost straight, 
or but slightly recurved, is emarginated at the extremity, and 
has seven or eight teeth above, and three beloAv. The fingers of 
the claws are somewhat longer than the hand. Common on the 
coast of F ranee and England 
The carpus is articulated, or presents annular divisions in tlie two 
folloAving genera, viz. 
* See the article Palemon, Encyclop. Method., and of the second edition of the 
Nouv. Diet. d'Hist. Nat., andDesmar., Consid., p. 2 . 36 — 238 . See also in relation 
to the nervous system, the Mem. Cit. of Messrs. Audouin and Milne Edwards. 
