528 
ZOOLOGICAL LITERATURE. 
OSTRACODA. 
Prof. Claus has made researches into the development of 
Cypris ovum, fas data, Kiod. vidua (see above, p. 510). The Ostra- 
codes undergo a metamorphosis during their free life ; and nine 
stages can be distinguished, each being marked by a moulting 
of the chitine integuments. In the first the larva is a Nauplius 
with two pairs of antennse and three pairs of other members, 
the third being still a leg, and not a mandible. In the second 
this leg is transformed into a mandibular palpus, the mandibles 
have their final form, and elements of the maxillae and of the 
first pair of perfect legs make their appearance. In thd fourth 
stage, which appears to correspond to the state of development of 
Cythere when leaving the egg, the maxillipeds make their first 
appearance (therefore later than the following pair of members, 
viz. the first pair of legs) ; they serve in the fifth stage as legs 
(as they do permanently in Cythere) and are then provided with 
a strong curved bristle at their extremity ; such a bristle is 
present in all stages of the metamorphosis, but in different 
members, — first in that which afterwards becomes the mandible, 
later in the first leg, then in the maxilliped, lastly, and perma- 
nently for the whole life, in the same first leg which had lost it 
n the fifth stage — during which it has been transformed from a 
simple short piece to a slender member with several joints. The 
posterior leg makes its appearance in the sixth stage. In the 
seventh all members have their final shape, and the elements of 
the sexual organs make their first appearance ; their further de- 
V lopment, and the differentiation between the sexes, belong 
to the eighth ; the development of sexual orifices and the rccep- 
taculum semiuis to the ninth and last. 
G. St, Brady has published, in the Transactions of the Lin- 
nean Society, vol. xxvi. 2nd part, a very elaborate Monograph 
of the British Ostracoda, in which he describes the genera and 
about 140 species, figuring all, except some which he could not 
recognize himself and one or two which he received too late. 
The localities are carefully noted, and a geographical table at 
the end of the monograph is added. 
The families are arranged in the following manner : — 
Sectio Podocopa : Fain. 1. Cypridee ; 2. Cytheridee. 
Sectio Myodocopa : Fam. 3. CypridinidcB j 4. Entomoconchidee (no British 
species) ; 6. Conchoeciadce. 
Sectio Oladocopa: Fam. 6. Eolycopidce. 
Sectio Platycopa : Fam. 7. Cytherellidce. 
The majority of Cypridee, but not all, are inhabitants of fresh 
water, that of Cytheridee and the few species of all the other 
families are marine. Cyiheridea torosa (Jones), Cythere pellu- 
cida (Baird),, and Loxoconcha etUptica (Brady) arc plentiful in 
salt marshes, in company with several Foraininifera. 
