TALITEUS. CRUSTACEA. 175 



Gen. 9. TALITRUS. Lat. Astacus, Pen. 

 The two anterior feet larger than the two following ; second 

 pair short, slender, terminated by two compressed joints, the 

 last in the form of a flattened membranous claw ; last three 

 pairs long, and terminated by a simple hook ; segments of 

 the body with lateral scales ; tail of five joints, of which the 

 last is the smallest. 



The animals of this genus swim on their side like the Gammari, or drag them- 

 selves along the sand. They assemble in great numbers on the dead animals thrown 

 ashore by the tide. 



T. locusta, Lat. (C. gammarus saltator, Mont.) Body cinereous, 

 with the antennae reddish and hairy. Very common on sandy 

 coasts. B Pen. Brit. Zool. iv. 28. 



Gen. 10. ATYLUS, Leach. Gammarus, Fab. 

 Upper antennae with the second joint longer than the third ; 

 under ones with the second joint somewhat shorter than the 

 third ; eyes subprominent, rounded, inserted between the an- 

 tennae ; tail with three double styles on each side, and above 

 with one moveable style ; body compressed. 



A. carinaius, Leach. Head with the rostrum descending ; five last 

 segments of the abdomen carinated, and acutely produced be- 

 hind. 14 lines long Zool. Mis. ii. pi. 69. 



Gen. 11. COROPHIUM, Lat. Cancer, Lin. 

 Antennae of four pieces, the inferior much larger and thicker 

 than the superior, with their last piece of four joints, and ap- 

 pearing to terminate in a small hook ; four anterior feet mo- 

 nodactyle, nearly equal ; body cylindrical, slightly compres- 

 sed, terminated posteriorly by jointed appendages. 



C. longicorne, Lat. (C. grossipes, Lin. Oniscus volutator, Pall.) In- 

 habits coasts of Europe Lin. Trans, xi. 362. 



Gen. 12. PODOCERUS, Leach. 



Fyes prominent ; four anterior legs monodactyle ; other cha- 

 racters of the preceding genus. 



P. variegalus, Leach. Body varied with red and white. Coasts of 

 England, among confervae and corallines. Lin. Trans, xi. 361. 



Gen. 13. JASSA, Leach. 



Eyes not prominent ; four anterior legs monodactyle, with oval 

 hands ; second pair largest, dentated on the internal margin ; 

 other characters of the Corophia. 



J. pulchella, Leach. Thumb of the second pair of legs with its in- 

 ternal edge notched at the base ; colour white, shaded with red. 

 Inhabits coasts of Devonshire, on fuci. Lin. Trans, xi. 361. 



Gen. 14. PHRONIMA, Lat. Cancer, Herbst. 

 Two very short setaceous antennae, composed of numerous joints; 



