296 
ZOOLOGICAL LITERATURE. 
Prof. Grube describes the following new species from Lussin (Die Insel 
Ijussin, p. 76) : Sphcsroma tridentulum^ Sph. emarginatum, Sph. ruhropunc- 
tatiim, and Acherusia (?) complanata. 
loOTHEIDiE. 
Idothea whitd and I. urotoma, Stimpson, Proc. Ac. Nat. Sc. Philad. 1864, 
p. 155, from Puget Sound. 
^GIDAS. 
^ga hellicepSy Stimpson, Proc. Ac. Nat. Sc. Pliilad. 1864, p. 155, from Puget 
Sound. 
Anceid^. 
M. Hesse, in a very elaborate memoir first published in the 
‘ Recueil des Savants Etrangers/ and since in a separate volume 
(Memoire sur les Pranizes et les Ancees, 4to, 74 pp., Paris, Lon- 
don, New York), has demonstrated that the Crustacea known as 
Anceus and Franiza are merely different forms of the same 
animal. He contends ; 
“ 1 . That the Franiza is but a phase of the metamorphosis of 
the larva of Anceus^ which is the perfect state. 
2. That during the period of the larval condition, which is 
continued for a very considerable time, the differences of the 
sexes are inappreciable; these Crustacea metamorphose themselves 
into males or females according to their predestination. 
3. That the male and the female are completely distinct in 
their form, and that they differ so very much between them- 
selves, that it would be difficult to believe that they belong to one 
and the same species, if they had not been traced throughout 
their various transformations. 
4. That previously toM. Hesse having described it, the female 
of Anceus was unknown. 
'^5. That these curious Crustacea present this singular pecu- 
liarity, that their life is divided into two very distinct periods, — 
the first, dmdng which they live as parasites, in the state of 
Franiza,vii^oii fish, at which period they are sanguivores, and have 
the organs of the mouth appropriate to their destiny ; the 
second, in the sta-te of Anceus ^ when, after having quitted the fish, 
they live in the earth, -hud then the form of their mouth under- 
goes a great modification, it appears to consist of lamellous 
appendages and strong mandibles. 
6. Lastly, that the state of Anceus is their latest metamor- 
phosis. The prolonged, probably unprecedented, observations 
that the author has been able to make on the duration of the life 
of these Crustacea, afford evidences which show it to be of con- 
siderable length. 
To the first of these clauses M. Hesse has appended a note, in 
which he says tliat his discovery was contested almost immediately 
(Annals and Magazine of Natural History for Sept. 1858) by Mr. 
