CRUSTACEA. 
279 
PaGURIDA5. 
Eupagurus kennerlyi, sp. n., Stimpson, Proc. Acad. Nat. Sc. Philad, 1864, 
p. 163, from Puget Sound. 
MACRURA. 
Palinurid^. 
M. Alphonse Milne-Edwards has made a very interesting 
and eurions observation (Comptes Rendus, tom. lix. p. 710) on 
the abnormal transformation of one of the organs of vision into 
an antenna. 
The speeies {Palinurus penicillatus, Olivier) formed part of a 
considerable quantity of Crustacea from the Mauritius, which 
had been sent by M. Roget de Bellouget to the Paris Museum. 
On the right side, the appendages of this large crustacean 
present nothing abnormal : the first somite of the head sup- 
ports, as ordinarily, a pedunculated eye ; the second carries the 
first or internal antenna ; and the appendage to the third is the 
large second antenna. On the left side they are found symmetrical 
with those on the right of the second and third somites ; but the 
ophthalmic somite instead of carrying an eye supports a long 
multiarticular filament, resembling the terminal flagellum of 
an antenna. The ocular peduncle is preserved in its ordinary 
form; and a portion even of a rudimentary cornea is distin- 
guishable at its extremity, from the centre of which arises the 
flagellum, which is about 4 centimetres in length. It is mi- 
nutely articulated, and furnished with hairs upon the superior 
border of the terminal division, a character that is equally appli- 
cable to the secondary branch of the first antenna.^^ 
Monstrous developments of this kind appear to be very rare 
among animals. An occasionally abnormal production of the 
great chelae of the edible crab is known. And a case has been 
placed on record in which the organs of generation are deve- 
loped as male organs upon one side, while they ate female on the 
opposite. But neither of these assimilate to that described by 
M. Alphonse M. -Edwards, which he considers to resemble the 
transformations that are found in plants, and by which we may 
be enabled to trace the origin of the several parts by dis- 
covering to what they will return, as soon as the developing 
force of any particular organ is withdrawn. 
It would have been a matter of interest if we could have 
been told whether this abnormal production was the result 
of an accidental injiiry, and thus nature, in her efibrt to re- 
produce an organ of vision, only produced an imperfect an- 
tenna, or whether it was a monstrous organ from its first pro- 
duction, and reproduced from each successive moult in an. 
enlarged form. 
