. Te, ogre 
CRUSTACEA. 659 
Add genera: Cerapus Say, Atylus Lracu, Podocerus Leacn, &c. 
Comp. Mitne Epwarps, Hist. Nat. des Crust. ut. pp. 58—70. 
Genus Lrichthonius MitnE Epwarps, on the authority of Kroryer, 
does not differ from Podocerus, but rests on a sexual difference of 
the males. Zidsskr. 1v. 1842, pp. 163, 164. 
B. Four first segments of trunk with epimera large, covering 
the bases of feet. Abdominal feet six; the last terminated by 
styles, serving with the apex of the incurved tail for jumping. 
Body depressed. Anterior either all or the inferior terminated 
by a filament setaceous, multiarticulate. 
Talitrus Latr. Mandibles furnished with a rudiment only of 
palp or destitute of palp. Superior antenne not longer than head, 
shorter than the pedicle of inferior; inferior elongate. 
Genera: TValitrus and Orchestia Leacu. 
Sp. Talitrus saltator Epw., Cancer locusta L., Pawn. Spic. Zool. 1x. Tab. 4; 
fig. 7, DesmMaAR. Crust. Pl. 45, fig. 2, Cuv. R. Ani. éd. ill., Crust. Pl. 89, 
fig. 3. This little animal, about 3” in size, is very common on the Dutch 
coast, where it is constantly progressing in the sand by jumping. 
Orchestia is distinguished by the sheer-shaped form of the first and 
second pairs of feet; the second pair has a large oval joint at the apex, on 
which the moveable curved claw is set; here belongs Orchestia littorea 
Leacu, Baster Natuurk. Uitsp. 1. Tab. 3, figs. 7; 8, Dmsmar. Crust. 
Pl. 45, fig. 3. 
Gammarus Latr. (Species from genus Gammarus FAsr.). 
Mandibles furnished with palp. Superior antenne always longer 
than the peduncle of inferior, sometimes longer than inferior 
themselves. 
Sub-genera: Lysianassa Epw. (Anonyx Kroryer), Alibrotus 
Epw. (Lysianassa previously), Phlias Guértin, Acanthonotus OWEN, 
Tsea Epw., Anisopus Tempiet., Amphitoé Leacu, Gammarus Epw., 
Ischyrocerus Kronyer, Leucothoé Lracu (Lycesta Sav.) and some 
others proposed by Kroryer I. 1. 
Sp. Gammarus flwviatilis Epw., Gammarus pulex Kocu, Reset Jns. 11. 
Suppl. Tab. 62; Koc and Grrvais distinguish this species as Gammarus 
Reselii from Gammarus pulec FABR., DESMAR. Crust. Pl. 45, fig. 8, Gam- 
marus fossarum Kocow in Hirricu-ScH&®FFrER Deutschl. Ins. Heft 138, 
Tab. 1. Linnaus has confounded not only these two species, but also 
42—2 
