490 
CRUSTACEA. 
tula; 21. Orithyia; 22. Corystes; 23. Leucosia; 24. Hepa- 
tus. 
Getius 22.—CORYSTES.— Latreille. 
Generic Character _Exterior antennae longer than the body, 
setaceous, ciliated, placed in two rows ; exterior feet-jaws with 
the third joint longer than the second; eyes seated on pedun¬ 
cles ; shell oval, longer than broad ; anterior feet large, equal, 
twice the length of the body in the male, and the same length 
as the body in the female, with forceps ; the other feet termi¬ 
nated by a furrowed claw. 
Corystes dentata. — The Toothed Corystes. 
Plate LXXXII. fig. 12. 
Granulated and crenated behind ; with a bind front, and the 
sides with three teeth. Inhabits the coasts of Britain. 
TRIBE IV.-CRYPTOPODA. 
Posterior angles of the shell dilated and vaulted; with very 
large, compressed, and crested forceps ; shell nearly triangular. 
—It contains two genera: 25. Clappa; 26. (Ethra. 
TRIBE V.-TRIGONA. 
With a subovoid or triangular shell, having the anterior extre¬ 
mity narrowed and pointed; claws frequently larger in the males 
than in the females.—It contains ten genera, namely: 27. Par- 
thenope; 28. Eurynome; 29. Pisa; 30. Maia; 31. Stenopus; 
32. Hyas; 33. Machus; 34. Macropodia; 35. Leptopodia; 
36. Pactolus; 37. Lithodes. 
Genus 28.—EURYNOME.— Leach. 
Generic Character. —With somewhat long external antennse, 
the first joint shorter than the second; shell ventricose, ante¬ 
riorly terminated by a bifid rostrum ; eyes distant, thicker than 
their peduncle; exterior feet-jaws having a nearly square third 
joint, and notched towards the middle of the internal side ; ante¬ 
rior legs equal, those of the male being three times the length 
of the body; the female with them somewhat longer than the 
body. 
