CANCROID E A. 



XANTHO FLOBIDUS, Leach, 

 - Madeira. 



The areolets are distinct over the anterior part of the carapax. 



1 L, however, is wanting or nearly so, 2 L, 3 L, are coalesced, and 1 M, 



2 M, are hardly separated. 2 M is simple. The teeth are the normal 

 ones, E, N, T, S; the outer angle of orbit (D) is not raised into a tooth. 

 A good figure of this species is given in Bell's British Crustacea, p. 51, 

 and another in Edwards's Illust. Cuv. Crust., PI. 11 bis, f. 3. 



XANTHO PLANUS (Edw.) 

 Valparaiso. 



Colour of specimens a dull brownish purple, at times spotted with 

 white or yellowish white posteriorly. None of the regions of the 

 carapax are distinct, yet a faint outline of the medial may be per- 

 ceived. The lateral tooth of the carapax is S, and another less dis- 

 tinct is T ; a faint fissure anteriorly separates the regions of E and N, 

 but there is no mark between D and E; and D itself is not at all 

 projecting. 



Length of carapax of a male, two inches and eleven lines ; greatest 

 breadth, four inches and three lines; ratio of length to breadth, 1 : 1'46. 

 In another male, length, one and thirteen-sixteenths inches ; greatest 

 breadth, two and thirteen-sixteenths inches ; ratio, 1 : 1'55. In a 

 female, length, two and five-sixteenths inches ; greatest breadth, three 

 and a half inches; ratio, 1 : 1-51. 



X. planus, M. EDWARDS, Hist. Nat. des Crust., i. 397, and Crust., D'Orbigny's S. 

 America, 14, pi. 6, fig. 1. 



XANTHO ORBIGNTI, 

 Callao, Peru. 



Length of carapax of a female, one and seven-sixteenths inches ; 

 greatest breadth, two and one-sixteenth inches; ratio of length to 

 breadth, 1 : 1*4 3. The areolation is rather faint, yet the medial 



