some British Fossil Crustacea. Les 
tail-flaps) 2 inches 2 lines ; length of hand 1 inch 3 lines, of 
carpus 4 lines, width of hand at middle 33 lines. 
This is most allied to the only other liassic species which I am 
aware of, namely the #. Hartmanni of Herman von Meyer (see 
his “ Beitrage zu Eryon” in the 18th vol. of the Nova Acta Acad. 
Ces. Leop. Carol. &c.), from which it differs m its much shorter 
abdomen, a character which approximates it to the otherwise dis- 
similar EH. subpentagonus (Mimst.) and LE. arctifermis (Schlot.) 
of the Kelheim and Solenhofen lithographic slates. In all the 
species described by Von Meyer and Miinster the hand and car- 
pus taken together equal or exceed the middle of the carapace in 
length ; this species 1s therefore most remarkably distinguished 
by the comparative shortness of its chel as well as their greater 
robustness. 
Rare in the lias of Barrow-on-Soar. 
(Col. University of Cambridge.) 
Archeocarabus (M‘Coy), n. g. 
Etym. apyatos, antiquus, and kapaPos, Aristotle’s name for the 
Palinurus or spiny lobster. 
Gen. Char. External antenne very thick and long, the sete of 
very short fimbriated joints ; first pair of feet much thicker 
than the others, the extremity of the penultimate joint dilated 
on its inner side to a broad, subtruncate, subcompressed hand 
as wide as the length of the curved terminal joint which is 
inflexed on it ; four posterior pairs of legs slender, compressed ; 
carapace semicylindrical, obtusely rounded above ; nuchal fur- 
row very wide and deep, extending with a gentle backward 
curve across the carapace in front of the middle ; cephalic por- 
Diagram of Archeocarabus. 
a. Portion of one of the outer antenne. 
tion depressed, front wide, subtruncate toothed, the lateral 
angles produced into large, flattened, slightly recurved spines 
over the eyes, shell below the orbits prolonged forwards into a 
thick spine; crust excessively thin and fragile, covered with 
