ORDER BRANCHIOPODA. 
347 
The Daphnia pulex , the most common of all, ( Monoculus 
pulex , Linn.) ; pulex aquations arborescens , Swamm. Bib. 
Nat. xxxi ; Perroquet cVeau , Geoff. Hist. Ins. ii. p. 455 ; 
Schceff. Die. Griin. arm. polyp. 1755, i. 1. 8.; Straus, Mem. 
du Mus. d’Hist. V. xxix. 1 — 20 ; Jurine, Mon. viii. — xi. has, 
according to M. Straus, the beak large and convex ; the setae 
of the oars plumose ; the first nipple of the sixth segment, in 
the form of a little tongue ; the valves denticulated at the in- 
ferior edge, and terminated by a short tail, obtuse in the 
females. This last character distinguishes it from another 
species, with which it has been confounded, the Z>. longispina , 
Sir. Deg. Insect. VII. xxvii. 1 — 4. 
See for the other species, the afore cited memoir of M. 
Straus: Muller, Entom. and Jurine Hist, des Monocles, se- 
cond family, pag. 185. 58. and p. 181 — 200. See also, for 
D. sima , and longispina , Ramd. Monoc. v. — vii. 
The last subgenus of the lophyropa is that of 
Lynceds, MlM. Chilodorus, Leach. 
Which is but little distinguished from the preceding, except 
by its oars, evidently shorter than the shell, and the lower 
portion of which makes little or no projection. According to 
M. Straus, the articulations of their branches should be more 
numerous than in the preceding subgenera ; all have in front 
of their eye a small spot, which has the appearance of another 
eye ; the beak is proportionally more elongated than that of 
daphnia, curved and pointed. 
See Mull. Entom. G. lynceus . Jurine, Monoc. pag. 
151 — 158; and Desmar. Consul. 375 — 378. 
The second section of branchiopoda, that ofPHYLLOPA, 
is distinguished, as we have said, from the first, by the num- 
ber of the feet, which is at least twenty, and by the lamellate 
or foliaceous form of their articulations ; the eyes are always 
