DEC A POD A. HOMOLADM. 



ANOMOUMA. 



GENUS LITHODES. Latr. 



Cancer, Linn. Herbst. 



Inachus. Fabr. 



Mai A. Bosc. 



LiTHODES, Latr. Leach, Edwards. 



Generic character. — External antennce placed nearly in a line 

 with the internal, on the outer side, and a little beneath them ; the 

 basal joint being, as it were, imbedded between the anterior mar- 

 gin of the carapace and a process or elongation of the lateral mar- 

 gin of the buccal opening, which is enclosed only at the sides, 

 where the margins are nearly straight ; the second joint is fur- 

 nished with a spine on the outer side, and the third is long and 

 cylindrical. Internal antennce long, inserted beneath and some- 

 what external to the eyes ; the first joint nearly cylindrical, thick, 

 and bent downwards and inwards ; the second and third cylin- 

 drical, slender, elongated ; the terminal portion consisting of two 

 short, setaceous, multiarticulate filaments. External pedijyalps 

 pediform, with the second joint short, broad, internally dilated and 

 toothed. Thorax with the posterior portion free and movable. 

 Anterior feet unequal, of moderate size, the fingers more or less 

 spoon-shaped ; the three following pairs very long, cylindrical ; the 

 fifth pair very small, adactylous, folded backwards beneath the 

 latero-posterior margin of the carapace. Carapace cordiform, with 

 the regions very distinct, spinous. Rostrum projecting horizontally. 

 E?/es not enclosed within orbits, but protected externally by a 

 strong spine ; the peduncles short, approximate. Abdomen large, 

 five-jointed. 



This very remarkable genus was formerly placed amongst 



the Oxyrhynchi ou account of the form of the carapace, 



M 2 



