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 fig. 20), weighed 16| 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, Cambarus pellucidus, and of the eyed crayfish, Cambarus 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 niue months, had eaten little and molted once. One 

 of the specimens of C. 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 (Pahemon 

 serraUis), which he kept in aquaria, varied from twelve to twenty- four days, depending 

 upon food, the temperature, and other conditions. When the cast skius 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 had partially buried its cast shell under the gravel. During the previous fortnight this 

 specimen has shown great irritability and pugnacity, and when offered food seized it savagely, but 

 instead of eating proceeded immediately to bury it. 



Spence Bate (3), who tried without success to observe the common green crab 

 (Carcinus mccnas) 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. 



Wheu the lobster is api>roachiug 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 



