498 
CRUSTACEA. 
JEga emargiiiata. — The Bordered 2Ega. 
Plate XCIV. fig. 7. 
Last abdominal segment laterally dilated, and much pointed ; 
interior lamella obliquely truncated internally, with an exterior¬ 
ly notched extremity. 
TRIBE III.-SPHiEROMIDES. 
Post-abdomen consisting of three segments, the last one pro¬ 
vided with a fin of two leaflets on either side.—The genera of 
this tribe are, 9. Anthura', 10. Zuzara; 11. SphaBroma; 12. 
Campecopea ; 13. Nsesa ; 14. Dynamene; 15. Cymodocea. 
Genus 9.—ANTHURA.— Leach. 
Generic Character —Antennae short, and not quite equal, 
the intermediate ones being somewhat longer than the lateral 
ones; body linear ; the anterior feet provided with a moveable 
claw ; tail having lateral foliaceous laminae. 
Anthura gracilis. — The Slender Anthura. 
Plate XCIV. fig. 9. 
Antennae short, somewhat equal, the intermediate a little 
longer than the lateral ones; body linear ; anterior feet with 
moveable claws ; tail foliaceous and obliquely truncated. 
TRIBE IV.-ASELLOTA. 
Last segment of the abdomen without swimming appendages. 
—The following are its genera: 16. Asellus; 17. Janira j 18. 
Jaera. 
TRIBE V.-IDOTEIDES. 
Post-abdomen provided with branchial appendages beneath, 
and covered by longitudinal doubly articulated plates; having 
four antennae placed in a transverse line, the lateral ones with a 
setaceous filamentous termination ; post-abdomen consisting of 
three distinct segments.—It has two genera : 19. Idotea; and, 
20. Stenosoma. 
Genus 19. — IDOTEA.— Fabricius. 
Generic Character .—Body either oblong or elongated, con¬ 
sisting of seven transverse segments; with setaceous lateral an- 
