vps 
LIMULUS. 
Limutus, Miller, Fabr., Latr., Leach. 
Monocunus, Linn., Gmel. 
Po.tyeHemus, Lamarck. 
CHARACTER GENERICUS. 
Corpus horizontale, clypeiforme: testa coriacea, duplex, 
antice rotundata, postice angustior ; antica major, sub- 
lunatus, convexus, tricarinatus, ocu/i duo ovati, minimi, 
sessiles vix prominuli, uno utrinque ad carinz lateralis 
latus inserto: postica subtriangularis postice truncato- 
marginata, lateribus utrinque dentatis spinisque mobili- 
bus instructis. Cauda cornea trigona scuti postici apicis 
emarginati medio ginglimo articulata. 
Mandibule due sub margine antico teste antice inserte, 
basi approximate, biarticulate, articulo secundo pollice 
mobili instructo. 
Pedes decem didactyli ; par quintum longius articulo pe- 
nultimo ad apicem lamellis quatuor elongatis. 
LIMULUS. 
GENERIC CHARACTER. 
Body horizontal, shield-shaped ; shel/ coriaceous, double 
rounded in front, narrower behind ; anterior shell larg- 
est, somewhat lunate, convex, with three carine ; eyes 
two, ovate, very small, sessile, and scarcely prominent, 
one on each side, being inserted on the side of the late- 
ral carina ; hinder shell somewhat triangular, truncate- 
emarginate behind, the sides toothed, having a move- 
able spine between each tooth ; tail horny, three-sided, 
