MORPHOLOGY AND FAUNAS. 
191 
phosis of the natatorial feet to the mandibles and maxillae, and 
the formation of a dorsal shield, both lying between the stages 
of Nauplius and Zoea, .are fully discussed. Then the author 
proceeds by acknowledging the existence of a gap between Zoea 
and the Phyllopods; but nevertheless he thinks probable that 
all the present orders of the Crustacea did originate from Phyl- 
lopoda. These separated tliemselves into two branches : some, 
remaining natatorial, and transferring the respiratory function 
from the dorsal shield to the natatorial feet, gave origin to all 
Podophthalma and Edriophthalma (the recent genus Nebalia is 
regarded as representing a link in tlie chain of this transforma- 
tion) ; others, losing more or less their natatory propensities, 
and developing the dorsal shield into a strong mostly bivalve 
shield sufficient for protecting the whole body, which becomes 
shortened for this purpose, gave origin to the Ostracods, Cirri- 
peds, and even to the Copepoda. The Trilobites belong also to 
this stage of historical development. The question whether the 
Ostracoda can be reduced to transformed Pliyllopoda, which 
Prof. Claus is inclined to maintain and F. Muller to deny, is 
fully discussed, chiefly with regard to the organization of the 
genus Cypridina, and fully upheld. Jen. Z. Nat. vi. pp. 96- 
156. 
In some specimens of Astacus {Chcrops) preissii (Erichs.), wliich have the 
internal and external male organs well developed, an analogue of the orifice 
of the female organs has also been observed in the chitinous tegument by 
the Recorder. SB. nat. Fr. 1870, p. 1. 
Contributions to Faunas. 
A. Metzger gives a list of Crustacea observed hitherto on the coast of 
East Friesland (between the mouths of the rivers Ems and Jahde), contain- 
ing 24 species of Decapoda, 19 Amphipoda, including 2 Lcemodipoda, 7 Iso- 
poda, 6 free Copepoda, 10 parasitical Caligidse and Lernfeidm, 8 Cirripeda (and 
3 Pj^cnogonida). Their modes of occurrence are accurately stated. JB. Ges. 
Ilannov. pp. 31-33. 
The Gammaridie (3 species), Lynceidfe (6), and Cypridm (23) of the fresh * 
waters of Belgium are given by F. Plateau, M6m. conr. Ac. Belg. xxxiv. 
1869-70; the Daphniidm and Cyclopidae in the following volume (xxxv.), 
1870. 
The Ostracoda of the tidal rivers of the eastern parts of Eng- 
land, especially the tidal lakes or broads of East Norfolk, 
have been examined by II. G. Brady. Although the water of 
most of them is perfectly fresh, there have been found many 
new and highly interesting species and even genera, the most 
characteristic of which are Gonioeypris mitra, Metacypris cor- 
data, Folycheles stevensoni, and Cythere fuscata. Some of them 
have been found also in the Dutch rivers Meuse and Scheldt. 
The author is not inclined to ascribe the presence of these and 
