132 
BRITISH ENTOMOSTRACA. 
cilia long ; striated or ribbed longitudinally, the ribs 
rather distant. Beak rather blunt. Eye areolar. 
Superior antennae conical-shaped ; inferior, or rami 
(t. XVI, f. 4 b), short, the setae also being short ; anterior 
branch having four, one from second and three from last 
articulation; posterior branch has three from last joint only. 
Upper part of body rounded, as in Acroperus harpce l 
Abdomen (t. XVI, f. 4 c) rather narrow, sinuated near 
extremity, and serrated for about half its length on the 
under edge, the serrae or teeth , at extremity being the 
largest. Terminating claws long. 
Intestine convoluted once, and nearly a half, but not 
so distinctly visible as in the other genera.* 
Hab . — Ditch near Richmond ; pond at Osterly Park ; 
and near Hounslow. In the Pease-burn, Cockburnspath. 
Pool on Bowmont Water, Yetholm, Roxburghshire./? 
2. Alona reticulata. Tab. XVI, fig. 3. 
Alona reticulata, Baird, Ann. and Mag. Nat. Hist., ii, 93, t. 3, f.12, 
1843 ; Trans. Berw. Nat. Club, ii, 151. 
In size this is perhaps the smallest of all the species of 
this family, being still smaller than the Acroperus nanus. 
Shell of a quadrangular shape, rounded a little poste- 
riorly, and nearly straight on anterior margin, which 
* I bad some doubts at first as to this being identical with the Monoculus 
striatus of Jurine. In his figure the beak is blunter, and the abdomen 
shorter and rounder-shaped than in my specimens. He gives it the name 
striatus with a doubt ; and remarks, “ if this species be the truncatus of 
Muller, as we may presume it is, it must be confessed that its specific name 
is improper; for the shell is not truncated, it is obliquely striated and 
strongly ciliated” (1. c., p. 154). It is evident that Jurine could never have 
seen the truncatus of Muller, and the quadrangularis seems also not to 
have been known to him ; for the difference between this species and the 
truncatus is so great and evident, that they cannot be mistaken for each 
other ; while the similarity between it and the quadrangularis is so decided, 
that notwithstanding the slight discrepancies mentioned above, I have now 
little or no hesitation in referring them botli to the same species. 
