60 
BRITISH ENTOMOSTRACA. 
and pressed upon by the stiff hairs which form the 
branchiae, then by the papillae, lastly by the jaws, they 
arrive at the mandibles, reduced nearly to pulp, and they 
are swallowed as any other substance would be.” Their 
enemies, in such]a fluid as the Artemia inhabits, are not 
numerous • but their chief foe is a small beetle, allied to 
theDytiscus, which M. Joly observed at Montpellier, and 
proposes to name Hydroporus salinus. When it meets 
an Artemia, it darts at it and bites it ; it then retires for 
a short time, but returns to the attack again and again, 
till it succeeds, by numerous bites, in killing the poor 
creature, and devouring it with astonishing avidity. 
The act of copulation does not appear to have been seen 
by any observer except Schlosser, who says the males 
seemed to be very eager to leap upon the backs of the 
females, and kept tight hold of them by their prehensile 
antennae. “ United thus, they remain some time to- 
gether, and scarce are they separated when others take their 
place.” The females appear to take the males even when 
they have already eggs in their external ovary, as Schlosser 
says he has observed the male embrace the female, in the 
part where the ovary is situate, so tight as to press out 
several ova; which causes him to remark : “ Je n’ose de- 
cider si cette action est une veritable accouplement, et si 
mes insectes a bras sont les males ou les accoucheurs de 
femelles, lT ay ant pas, par un tres bon microscope, vu 
aucun autre chose que ce que je viens de vous dire.” It 
appears, however, from M. Joly, who has isolated the 
females, that one fecundation must, as in most other En- 
tomostraca, suffice for more than one generation. 
The same author also asserts, that the Artemiae are both 
oviparous and ovoviviparous, according to the season of 
the year. Before July and after September they only lay 
eggs; while during summer they generally bring forth 
young. In about twenty-four hours after the young are 
born or the eggs expelled, the mother changes her skin. 
To effect this she rubs herself either against the sides of 
the vessel or against any foreign bodies she may meet with 
