"^'iSi!^,i:t" ^MMm in the Uni.

190
CRUSTACEA.
RICHIARDI, S. Bomolochus ostracionis. Arch. p. Zool. ii.
pp. 47-59, pi. 1.
SARS, MICH. Bidrag til Kundskab om Christianiafjordens
Fauna. II. Crustacea. Christiania: 1870, 8vo, 48pp. 3pis.
SMITH, SIDNEY F. Notes on American Crustacea. No. 1.
Ocypodoidea. Tr. Conn. Ac. ii. 1870, 84 pp. 8vo, 4 pis.
STREETS, T. HALE. Notes of some Crustacea of the genus
Libinia, with descriptions of four new species. P. Ac.
Philad. 1870, No. 3, pp. 104-107.
VERRILL, A. E. Observations on Phyllopod Crustacea of the
family Branchipidce. P. Am. Ass. 1869 [published July
1870]. 18 pp.
WAGNER, NICOL. [Hyalosoma dux, a new form of Amphipod
Crustacea. Transactions of the first meeting of Russian
naturalists at St. Petersburg, 1868, pp. 218-238, 4 pis.]
WRIGHT, EDW. PERCEVAL. On a new species of the genus
Pennella. Ann. N. H. (4), vol. v. p. 43, pi. 1.
MORPHOLOGY.
A. DOHRN publishes two papers concerning the common
points in the embryonic development and the probable common
origin of the different orders of the Crustacea. In the first he
points out not only that the Decapoda pass during their development
from the stage of Nauplius to that of Zoea (the suppression
of these stages, as in Astacus fluviatilis, being an exception),
but also that in the other orders of Crustaceans
there are traces which suggest the conclusion that they have
had in former times such a Zoea-stage; he regards the dorsal
spine as a very essential character of Zoea, and thinks that the
dorsal accumulations of cells in the embryos of some Isopods
and Amphipods, the so-called micropyle-apparatus in the Amphipods,
the dorsal sucker of the larva? of Limnadia and the
Cladocera, the frontal fixing apparatus of Caligus and Chalimus,
and the peduncle of the Cirripeds are to be regarded as transformations
of the dorsal spine of Zoea; several other hitherto
enigmatical organs in the larva? of .various Crustacea are interpreted
in the same way. Jen. Z. Nat. v. pp. 471-491.
In the second, very extended, paper he endeavours to trace the
probable origin of all groups of the Crustacea from a Nauplius,
which itself may have taken its origin from lowly organized
members of the class Vermes. Archizoea is regarded as an
intermediate stage between Nauplius and Zoea. The metamor-