206 CLASS CRUSTACEA. 



dactylous forceps. The appendages of the tail are six in 

 number, and in the form of stylets, elongated, forked, orbiden- 

 ticulate at their extremity. Six vesicular sacs are visible 

 between the final feet. It appears that there are many spe- 

 cies, but they have not been described in a comparative and 

 rigorous manner. The type is Cancer Sedentariiis, Forsk. 



In others the number of the antennae is four ; all the feet 

 are simple. The tail has, at each side of its extremity, a 

 lamellary or foliaceous fin, the laminae of which are pointed 

 or unidenticulate at the end. 



Hyperia, Latr., 



Whose body is thicker in front, whose head is occupied for 

 the most part by oblong eyes, a little emarginated at the in- 

 ternal edge, two of whose antennae are as long at least as one 

 half the body, and terminated by a setaceous stem, long, and 

 composed of many small articulations. {Cancer monoculoides, 

 Montague.) 



Phrosine, Risso. 



Similar, in the form of the body, and that of the head, to hype- 

 ria, but the antennae are at most only of the length of this 

 part, with but few articulations, in the form of stylet, or 

 terminated by a stem, in an elongated cone. (Phrosine ma- 

 crophthalma, Risso.) 



Dactylocera, Latr., 



Whose body is not thickened in front, whose head is of middle 

 size, depressed, almost squared, with the eyes small, and 

 whose antennae, very short, and with few articulations, are of 

 diverse forms ; the inferior being slender, and in the form of 

 a stylet, the superior being terminated by a small lamina, 

 concave at the internal side, and representing a sort of spoon 

 or pincer, {P/irosina Semilunata, Risso.) 



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