THE AMERICAN LOBSTER. 
83 
weighed not over 25 pounds. The shell of the last three joints of the claw-bearing 
limb (the parts represented in tig. 20), weighed 163 ounces. It has the thickness of 
thin pasteboard, excepting at the tips of the claw, where it is denser, and probably 
belonged to a lobster which had molted within three months of the time of its capture. 
Putnam {154) records some interesting facts in regard to the molting habits of the 
blind crayfish, Gambarus pellucidus , and of the eyed crayfish, Cambarm bartonii , cap- 
tured in Mammoth Cave November 13. The blind species was of a milk white color. 
One molted on January 29 and a second time April 20. Another specimen of this 
species, exposed to the light over nine months, had eaten little and molted once. One 
of the specimens of G. bartonii molted about February 20, and when observed was 
eating its own shell. It had devoured about half of it. This habit of eating the remains 
of the old shell is very interesting, and is undoubtedly induced by the need of lime. 
It was noticed in the crayfish by Baker (7) over a hundred years ago, but it is so 
seldom recorded that it would hardly seem to be a fixed habit. It is probably 
occasionally practiced by the lobster and all the higher Crustacea, especially when in 
confinement. Warrington {199) estimated that the molting period of prawns {Palcemon 
scrrattis), which he kept in aquaria, varied from twelve to twenty-four days, depending 
upon food, the temperature, and other conditions. When the cast skins were not 
removed the prawns devoured all the soft parts. Young lobsters, immediately after 
molting, fill their stomachs with any calcareous matter at hand, such as the fragments 
of the shells of mollusks and Crustacea. Pieces of the integument of the lobster are 
commonly found in the stomach-bag, so that it is not at all improbable that the young 
lobster sometimes devours its cast-off skeleton. Brook {26) thus speaks of a lobster 
the day after ecdysis : 
It Lad partially buried its cast shell under the gravel. During the previous fortnight this 
specimen ha,s shown great irritability and pugnacity, and when offered food seized it savagely, but 
instead of eatiug proceeded immediately to bury it. 
Spence Bate (5), who tried without success to observe the common green crab 
( Carcinus mcenas) in the act of molting, concluded that this animal had the power of 
inhibiting the process until a favorable time arrived. 
THE CASTING OF THE SHELL. 
A male “shedder” was caught in the harbor of Woods Hole July 13, 1891, and' 
placed in an aquarium. At exactly 2.48 p. m. this lobster began to molt and in six 
minutes was out of its shell. 
When the lobster is approaching the critical point the carapace or shell of the 
back gapes away a quarter of an inch or more from the tail. Through the wide chink 
thus formed the flesh can be seen glistening through the old and new cuticle, giving 
it a decidedly pinkish tinge. Take the lobster up in the hand now and the tail 
drops down as in death, the strong muscles which bind the pleon to the carapace being 
completely relaxed. When this stage is reached the time of exuviation is at hand 
and the process becomes purely automatic, the animal having lost all control over its 
own movements. There are other signs, though not equally infallible, which point to 
the same conclusion — the dull, faded colors of the old shell, scratched and marred 
often with the marks of many conflicts. The shell is frequently of a dark, dirty green 
color, the mottled tints having become very much obscured. The contrast in color is 
very great if the shedder happens to be among a lot of new-shell lobsters, and the 
