1880.] 
83 
[Hyatt. 
General Meeting. November 3, 1880. 
The President, Mr. S. H. Scudder, in the chair. Forty-nine 
persons present. 
Messrs. NT. A. Francis, John C. Phillips, Joel Goldthwaite, and 
Mrs. S. L. Becker were elected Associate Members. 
The following paper was read : 
MOULTING OF THE LOBSTER— IiOMARUS AMERICANUS. 
BY ALPHEUS HYATT. 
Our knowledge of the moulting period in the Crustacea is sin- 
gularly deficient. 
The Cray-fish has been closely observed, ,but no exjilanation has 
yet been given even here of the phenomena of absorption, or 
what part it plays in j^rejiaring the shell for the act of exuviation. 
Several species of Brachyura have been observed, but the same 
deficiency exists in this respect also, since no explanation has been 
given of the mode in which the cephalo-thoracic rings are cast 
off, which is really acconrplished by the absorption of a consider- 
able part of them. 
The lobster has been observed several times during the moult- 
ing period, though it is quite remarkable that no jmofessional 
naturalist has actually seen the process and recorded his own 
observations. 
Reaumur described the moulting of the Fresli-water Cray-fish 
as early as 1712-1718 and his account has been confirmed and is 
still quoted. According to these observations the Cray-fish creeps 
out of his shell by an orifice formed by the splitting transversely 
of the soft integument on the dorsal side between the carapax 
and the first abdominal ring. Room is made by the elevation of 
the carapax and the protrusion below of the thoracic rings and 
the appendages. 
