166 Prof. F. M'Coy on the Classification of 



tened, anterior half abruptly sloped downwards towards the 

 front ; whole surface even and nearly smooth, the only regions 

 defined are the cardiac and intestinal, which are marked by 

 shallow furrows (P. Peruvianus) ; sides minutely granular ; 

 abdomen of the female broad oval (apparently of seven joints) ; 

 four hinder pair of feet subequal, slightly compressed, very 

 long, the thigh (or third joint) alone equaling the posterior 

 lateral margin of the carapace in length ; chela short and 

 strong. 



So far as the imperfection of the specimen allows of examina- 

 tion, the most striking difference between the present genus and 

 the recent Pilumnus consists in the great proportional length of 

 the legs, which are rather longer and more slender than those of 

 the Galene Natalensis of Krauss (see his Siidafrikanischen Crust. 

 1. 1. f.4), to which it bears some resemblance; the tail of the female 

 is more ample, and the tumid rounding of the antero-lateral mar- 

 gins and their small uncompressed spines contrast strongly with 

 the similar parts in the recent genus. The only two known spe- 

 cies are the following, and the so-called Portunus Peruvianus 

 figured by D'Orbigny in the geological volume of his great ' Voy- 

 age dans PAmerique meridionale' (t. 6. f. 17), of uncertain ori- 

 gin, but which he suspected to have come from the cretaceous 

 beds of the Cordillera ; a view I think confirmed by the geological 

 place of the second species of the genus, which therefore at pre- 

 sent would seem confined to the cretaceous system, and is I be- 

 lieve the oldest of the genuine Brachyura known. 



Podopilumnus Fittoni (M'Coy). 



As this is the only accessible species of the genus, it will be 

 sufficient, in addition to the above characters, to add the following 

 particulars : — Length of carapace 1 inch 5 lines, width 1 inch 

 9 lines, general surface smooth, sides minutely granular ; hands 

 about 7 lines wide and 1 inch 1 line long, the obtusely keeled 

 upper edge with five or six obtuse tubercles, the outer surface 

 minutely shagreened and bearing three or four irregular longi- 

 tudinal rows of small tubercles ; fingers short, curved, rounded 

 on the outer edge, and with three or four blunt teeth on the inner 

 edge ; tail 6| lines broad, only the five proximal joints preserved, 

 but the fifth being about the same length as the fourth, it 

 is probable the remaining two were distinct, it being generally 

 at that part of the tail that anchylosis occurs in those genera 

 which have less than the normal number of abdominal or tail 

 segments. 



Greensand of Lyme Regis. 



(Col. University of Cambridge.) 



