26 PHRONIMID®. 
derable development, although still shorter and compara- 
tively more robust than in the perfect animal. The eyes, 
in the perfect state, have afforded very interesting details. 
In addition to the lateral pair of the ordinary form, 
connected with the lateral extremities of the brain, are a 
superior pair of organs of sight, the nerves of which are 
considerably elongated, arising from intermediate dila- 
tations of the brain, and terminating in a mass of small 
knobs. The basal portion of these nerve-filaments 
forms a dark red mass, so that, in these respects, the 
animal is quite analogous to Ampelisca Gaimardii, described 
in our Vol. i. p. 128. 
The only specimen of this species which we have seen 
as a native of the British coast, is one in the British 
Museum, taken by Dr. Fleming on the 3rd November, 
1809, at Burray, in Zetland, amongst rejectamenta of the 
sea, This specimen, unfortunately, is in a very dilapi- 
dated condition. We have, therefore, found it necessary 
to present our readers with a figure drawn from a speci- 
men of unknown habitat, with which we have compared 
the British type. Other specimens from the Shetland 
Islands were obtained by the late Dr. Johnston, and 
exhibited by him before the Berwickshire Naturalists’ 
Club in 1855 (Proceedings, iil. p. 212). 
The animal is more abundant in warmer latitudes; 
and the fact of its having been found so far north is to be 
attributed, probably, to the currents of the Great Gulf 
Stream. Risso describes the animal as being transparent, 
shining, and covered with red spots. Desmarest says 
that it is to be found mostly in the cavities of Pyro- 
soma and Beroe. Several specimens of the Phronime 
within the latter animals, open at both ends, are pre- 
served in the Hopeian Collection at Oxford; the cavity 
of the latter, in one instance, containing a large num- 
