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REPORT ON ZOOLOGY, MDCCCXLII : 
yellowish yolks, surrounded by a thin membrane. At a later period an 
embyro is formed in the middle of each yolk, which, on farther develop- 
ment, verges to the side of the shell, when having reached the size of ten 
millim., and with two convolutions, the fcetus breaks through and escapes. 
(Institut. 1842, p. 43.) 
Some remarks are added, at the same place, by Laurent, on the egg 
capsules of the Valvata piscinalis. These capsules are globular, affixed 
to some body under water, and contain ten to twenty eggs, surrounded 
by a common glaire. Each has its separate shell, ending in a twisted 
thread at each pole, and only one yolk. When the development of the 
eggs is far advanced, the capsule is torn asunder, and the eggs come out ; 
some days later the covering of the individual egg opens and lets the 
embryo escape. 
Laurent mentions, in the same place, that seminal animalcules are 
found in the egg of the Limax agrestis. He says also, that the grape- 
formed organ in the Hermaphrodite Snails, which contains, in its paren- 
chyma, seminal animalcules and eggs, is provided with a single outlet, to 
convey the egg and the seminal animalcular fluid into the first chamber 
of the matrix ; while, at the same time, the secreting organ of the glaire 
supplies the necessary proportion of jelly. The matrix only supplies 
that portion which forms the egg-shell ; and this gradually thickens the 
nearer the egg is to its exit. The author possesses a preparation of a 
Limax ater, which died during the formation of the egg. 
CEPHALOPODA. 
Milne Edwards lias given, in the Annales des Sciences 
Natiirelles, xviii. p. 331, a full account of the Spermatophora 
of the Cephalopoda, in continuation of his observations 
made with Peters in Nizza, and already mentioned in the 
former year’s Deport. Four plates belong to this treatise, 
the last of which exhibits the male organs of generation of 
the Sepia officinalis. 
A. Krohn has given some additional remarks on the 
Structure of the Eye of the Cephalopoda, in the Leopoldiner 
Acten. xix. 11, p. 41. 
D. Ball exhibited to the Irish Academy the following 
Cephalopoda, as a contribution to the Fauna of the Irish 
Sea. (Ann. Nat. Hist. ix. p. 348) : — 
