676 CLASS X. 
quadrate, receiving the fourth joint at the internal angle of the 
superior margin. External antenne with seta pretty long, sub- 
ulate, with elongated joints, first joint large, grown to the shell, with 
the external margin shutting in the orbit beneath. Shell mostly 
longitudinally triangular, or oval, spinose, with rostrum bicornute. 
Abdomen in most composed of seven segments. 
Pisa Leacu (and Lissa ejusd.). Add sub-genera: Hyas Leacu, 
Mycippa Lracu, Leucippa Evw., Pericera Latr., Herbstia Epw. 
Sp. Wyas araneus LEacn, Cancer araneus L., Cuv. R. Ani., éd. ill., Crust. 
Pl. 33, fig. 2, Benn Brit. Crust. p. 31. 
Maja Lam. (exclusive of several species). Add sub-genera: 
Acanthonyx Latr., Chorinus Leacu, Mithra Leacn and some 
others. Comp. Dr Haan 1.1. pp. 81—83. 
Sp. Maja squinado Latr., Cancer squinado HERBST, DESMAR. Crust. Pl. 21, 
BELL Crust. p. 39; on the 8. and W. coasts of England, in the Mediter- 
ranean, &c. 
Parthenope Fasr. First pair of feet very long, geniculate at 
the chela, remaining feet moderate. (Third joint of maxilliform 
feet as in Maja.) Basal joint of external antenne not concrete 
with shell, not closing the orbit. Shell mostly triangular, often 
broader than long, tuberculate. Rostrum short. 
Parthenope Fasr., Lnacu (and Larabius LEacn). 
Sp. Parthenope horrida, Cancer horridus L., Rumen. Amb. Rariteitk. Tab. 
1x., Desmar. Crust. Pl. 20, fig. 1; from the Indian Ocean. 
(Ethra Leacu, Lam. 
Cryptopodia Epw. 
Note.—These sub-genera, scarcely distinct, differ from Parthenope in the 
feet, as in Calappa, concealed under the shell. 
Family XXXIV. Cancrina (Arcuata and Quadrilatera LATR., 
Catometopa and Cyclometopa Epw.). Space between the origin 
of middle antennze and area of mouth short, transverse, much 
broader than long. Shell never running anteriorly into a frontal 
rostrum. 
A. Fourth joint of mazxilliform feet placed upon the middle apex 
or the external angle of third joint. 
Shell mostly subquadrate or trapeztform, with frons declining or 
perpendicularly inflected. 
