ORDER DECAPODA — LITHODES. 17 



{EXTRALIMITAL ) 



Genus Ilia, Leach. Shield oval or circular. An'erior feet very long-, slender, and terminating in long 



filiform fingers. 

 I. punctata. (Edw. Vol. 2, p. 125. Leucosia id. Say, loc. cit. p. 457.) Shield with three long 



conical teeth behind, directed backwards. Surface granular, terminated by a granulated margin. 



Coast of Georgia and Florida. 



Genus Hefatus, Lalreille. Shield broad, arched in front, narrowed and truncated behind. External 

 antennae short ; the four posterior pair of feet terminated by a small pointed tarsus. 



H- fasciatus. (Desmarest, Consid. pi. 9, fig. 2. Say, loc. cit. p. 457.) The antero-lateral mar- 

 gin of the shield divided into 12 - 13 more or less rectangular teeth, which are dentated on their 

 edges. Color, variable, yellowish; in the young, banded; in the adult, maculate with reddish 

 spots. Coast of Georgia and Florida. 



GENUS LITHODES. Latreille. 



Shield cordiform, tubercular ; the rostrum elongated. Eyes approximated, with the four 

 short antennae between them. The first four pair of feet successively longer ; the fifth pair 

 very short and rudimentary. 



Obs. This genus is one of a group which forms the transition between the Decapoda bra- 

 chyura and the D. macroura. It constitutes the section Decapodes anomoures of Milne- 

 Edwards. Of the genus Lithodes, we have as yet but one representative on our coast. 



LlTHODES ARCTICA. 



PLATE VI. FIG. 11. 



Cancer maia. Lin. Syst. Nat. p. 1046. 



Lithodei arctica. Latreille, Genera, Vol. 1, p, 40. 



i. maja. Leach, Zool. Miscell. Vol. 1, p. 40. Lam. Vol. 2, p. 414. Ed. Brux. 



L. arctica. Lat. in Griffith's Cuvier, Vol. 13, p. 172, pi. 1, fig. 1. 



L. id. Milne-Edwards, Hist. Nat. Vol. 2, p. 186. Godld, Invertebrata of Mass. p. 327. 



Description. Shield heart-shaped, covered with conical tubercles, and a series of large 

 pointed spines along its lateral margins ; the rostrum elongated, slender, bifid, or with two 

 slightly diverging points at the end, two pair of lateral teeth, and one above, and the other 

 larger one beneath the rostrum. Second joint of the external antenna? with a tooth on its 

 outer surface. Pincers with tufts of hairs. All the feet, except the last pair, with series of 

 stout spines. 



Length, 4 - 0. Transverse diameter, 3*5. 



This is a boreal species, very common on the coast of Norway. On our coast it is very 

 rare. Dr. Gould obtained, through Dr. Prescott of Lynn, a specimen from the stomach of a 

 codfish on the coast of Massachusetts ; and, under similar circumstances, it may present 

 itself to the naturalists of this State. 



Fauna — Part 6*. 3 



