CRUSTACEA. 643 
abdomen; a moveable appendage, resembling a rostrum at the 
anterior part of the shell. Four antenne, terminated by a long 
many-jointed seta, serving for swimming. Natatory feet bifid, in 
different number behind four pairs of branchial feet, lamellose. 
Sp. Nebalia Herbstit, Cancer bipes O. Fasr., Faun. Groenl. fig. 2, p. 246 ;— 
Nebalia Geoffroy Epwarvs, Ann. des Sc. natur. Tom. XII. 1828, pp. 297— 
300, Pl. xv. Guérin Jconogr., Crust. Pl. 32, fig. 2. Compare also 
Epwarpbs Ann. des Sc. nat. 2e Série, 11. pp. 300—311. To this genus 
belongs also Monoculus rostratus Monraau (Transact. of the Linn. Soc, X1. 
fig. 5), Nebalia Montagui THompson. 
B. Eyes sessile. 
Limnadia Bronantart. Body inclosed in a bivalve, oval, 
compressed shell. Antenne four, anterior short, undivided, pos- 
terior and exterior large, with a cylindrical peduncle and two 
branches setaceous, multiarticulate. Feet (eighteen to twenty- 
seven pairs) lamellose, bifid, with a filament at the base recurrent 
or ascending towards the back. Last segment of body terminated 
by two diverging filaments. 
Sp. Limnadia Hermanni AD. Bronentart, Mém. du Mus. vi. 1820, pp. 83 
—92, Daphnia gigas Herm., Mém. aptérol. Tab. v. figs. 4, 5, Kocu in 
Herricu-ScuaFrer Deutschl. Ins. Heft 185, Tab. 10 ;—Limn. mauritiana 
Guérin, Magas. Zool. 1837, Cl. vil. Pl. 21, figs. 1—11, Iconogr., Crust. 
Pls 33, fig. 2; 
Compare also J. Krynicxi, Des Limnadies in the Bullet. de la Soc. imp. 
des Natural. de Moscou, 11. 1830, pp. 173—182, Pl. vit. Limnadia tetracera. 
This writer found males, and observed the copulation. BRONGNIART 
observed only females. 
Eistheria RUEPPELL. 
Sp. Estheria dahalacensis Rurpr., StRavS DurcKHEIM, Museum Senckenber- 
gin. 1. 1837, pp. 117—128, Tab. vil. 
Apus Scumrr., Limulus Murwu., Lam. Shell produced from 
head over thorax and a great part of abdomen, clypeiform, thin, 
deeply emarginate posteriorly. Eyes two, approximate, including 
an ocelliform point. Two inferior antenne very short, styliform, 
biarticulate. Mandibles strong, gibbous externally, with internal 
margin straight, denticulate. Two pairs of maxille. Sixty pairs 
of feet; first pair incurved, filiform, with three very long setz 
exsert beyond the shell, multiarticulate ; remaining feet lamellose. 
Six last segments destitute of feet; two sete at the last segment 
long, multiarticulate. 
41—2 
