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



developed abdomen, caudal fins, remarkably large false feet, and 

 all the characters of the Macrura, being in fact clearly referrible 

 to the genus Mecochirus of Germar, so abundant in the upper 

 oolitic schists of Bavaria, though not hitherto recognised in Bri- 

 tain. The five internal processes mentioned on each side are 

 merely the indications of the apodemata or internal partitions 

 between the gills, and present no peculiarities. As the specific 

 name longimanus would be peculiarly inappropriate when this in- 

 teresting little crustacean is placed in its true genus (nearly all 

 the species of which have longer hands), it might provisionally 

 bear the name of Mecochirus Pearcei. 



[Macrura.) 



In this group we find several fossil Crustacea referred to recent 

 genera in British works, without, I believe, just reason : — thus in 

 Morris's Catalogue we find Palinurus Seurii quoted from Leeds, 

 Yorkshire ; — if this muschelkalk fossil is found there, it should 

 be placed in the Triassic genus Pemphix, formed many years ago 

 for it by Von Meyer, it having no relation to Palinurus. The 

 recent generic name Astacus has also been much used for fossils 

 of various ages, but I have not yet seen or heard of the real oc- 

 cuiTcnce of that genus in the fossil state ; most of the species will 

 be noticed below under their respective genera. 



Eryon Barrovensis (M^Coy). 



Sp. Char. Carapace subovate, about one-eighth broader than long 

 near the truncated posterior margin ; lateral margins set with 

 short tooth-like spines, two narrow incisions on each side, the 

 hind pair a little in front of the middle, inclosing between 

 them on each side a short rotundato-quadrate lobe ; front nar- 

 rowed, concavo-truncate, with the lateral angles slightly pro- 

 duced outwards ; each of the inner pair ofantennce having their 

 two setae deeply divided, the outer one of each slightly longest, 

 scale of the external antennae large, the setse scarcely thicker 

 than those of the inner pair ; abdomen exceeding the length of 

 the carapace by only one-third the length of the outer tail- 

 flaps, which latter are very broad and subquadrate at the end 

 (resembling those of the Eryon Hartmanni) ; each of the seg- 

 ments except the first bears a large, oblong tubercle in the 

 middle ; first pair of legs robust, short, hand and carpus to- 

 gether nearly one-fourth less than the length of the middle of 

 the carapace ; fingers very slender, both pointed, of equal 

 length, incurved at the tip, the moveable one most abruptly. 

 Surface minutely granulated, with larger granules on the me- 

 sial ridge of the carapace. Ijcngth of carapace 2 inches, width 

 2 inches 2 lines ; length of abdomen (to end of outer pair of 



