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



de Normandie, Morris's Catalogue, &c), and some similar forms 

 from the gault, form a peculiar genus intermediate between Ho- 

 mola and Corystes, and belonging not to the Brachyura but to 

 the Anomura, for which I have proposed the name Podopilumnus. 

 3. Inachus : Desmarest (Crust. Foss.), Morris (Catal.), and seve- 

 ral other authors have quoted a species of this genus as found 

 fossil in the London clay : — the figures and descriptions which 

 I give below, from the abundance of perfect specimens which I 

 have examined, leave no room for doubt that the fossil in question 

 does not belong to the Brachyura but belongs to the Anomura, 

 and forms a particular genus allied to Notopus, Dorippe and the 

 like, to which I have given the name Notopocorystes. 4. Corystes 

 (Latreille) : the gault fossils referred to this genus in Morris's 

 ' Catalogue ' belong to the same Anomurous genus as the so- 

 called Orithya. 



Zanthopsis (M'Coy), n. g. 



Gen. Char. Carapace suborbicular or transversely oval, gibbous, 

 strongly arched from before backwards; gastric region very 

 large, tumid, depressed in the middle towards the insertion 



Diagram of the genus Zanthopsis. 

 a. Entire animal as far as known ; b, view of the front from below, showing 

 the internal antennae lodged in their transverse fossae, and the position 

 of the outer pair in the inner canthi of the orbits ; c, abdomen of female, 

 nat. size; d, ditto of male, nat. size. 



of the genital region, which is very small, pentagonal, and not 

 extending more than one-third the length of the carapace to- 

 wards the front, generally divided by a transverse depression 

 into two portions, the hinder of which is most prominent and 

 equal in width to the cardiac and intestinal regions, which are 

 longer than broad, and form together a tumid ridge of three 



