62 CRUSTACEA. 



with prickles, and armed in front with stout, projecting, and more 

 or less numerous spines or teeth. Its colour, as also that of the tail, 

 consists of an agreeable mixture of red, green, and yellow. The tail 

 frequently presents transverse bands or spots, sometimes ocellated, 

 arranged in regular series. Their flesh, that of the females particu- 

 larly, before and. after the spawning season, is highly esteemed. 



In the species taken on the coast of France, and probably in others, 

 the extremity of the penultimate joint of the two posterior feet of 

 the female is provided with a tooth or spur peculiar to the sex. The 

 same ol)servation applies to the Scyllari. 



PaUnurus quadriconiis, Fab.; Astacus eZe/)/«as, Herbst., xxix, 

 1; Leach, Malac. Brit., xxx, or the Langoustt commune of the 

 French, is sometimes half a metre in length, and when loaded 

 with ova weighs from twelve to fourteen pounds. The shell is 

 spinous and downy, with two stout teeth notched beneath, be- 

 fore the eyes. The superior surface of the body is of a greenish 

 or reddish brown; the tail is spotted and dotted with yellowish, 

 and its segments are marked by a transvei'se sulcus interrupted 

 in the middle, its lateral edges forming a dentatcd angle. The 

 feet are picked in with red and yellowish. It inhabits the coasts 

 of France, that of the Mediterranean in particular. It is found 

 fossil in Italy(l). 

 The third section, that of the Astacini, Latr., is distinguished 

 from the preceding by the form of the two anterior feet, and fre- 

 quently by that of the two following pairs, which terminate in a 

 forceps with two blades, or a didactyle hand. In some, the last two, 

 or four, are much smaller than those which precede them, therein 

 approaching the Anomala; but the fan-like fin of the extremity of 

 their tail and other characters remove them from that section. The 

 thorax is narrow anteriorly, and the front projects in a pointed snout 

 or rostrum. 



Some of them, — Galaihadeae, Leach, as well as the preceding Ma- 

 croura, have four pairs of false feet; the mediate antennae flexed like 



(1) M. Desmarest, Hist. Nat. des Crust. Foss., p. 132, speaks of two other fossil 

 species, the second of which, however, may probably belong to the subgenus As- 

 taceus properly so called, and approacli the Jl. nonvegicus of Fabricius. 



For the other living species, see Ann. du Mus. d'Hist. Nat., t. Ill, p. 391,etseq. ; 

 the article Palinure, Encyc. Method., and its Atlas d'Hist. Nat.; that of Langouste, 

 Nouv. Diet. d'Hist. Nat., Ed. H, and the same in the work of Desmarest on the 

 Crustacea. As respects the nervous system of the species that inhabits the French 

 coast, see Audouln and Edwards, op. cit.; according to them, all the thoracic gan- 

 glions are as if soldered together, end to end. 



