78 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



of the large claw are stretched out like a stick of candy, and are drawn through an 

 opening- at the base of the second joint, the area of which is less than one-fourth that 

 of a cross section through the largest part of the claw. The shell of the back, or cara- 

 pace, conies off entire, as a rule, but occasionally it is split along the line of absorption 

 and is thus partially separated into two halves. 



At the time of shedding a considerable store of lime has been laid down in the 

 walls of the stomach, probably for the rapid hardening of the lining of this organ or of 

 the shell. It is in the form of two glistening white masses, one on either side, and 

 each about the size of a small filbert. These gastroliths, better known in the cray- 

 fish as " crayfishes' eyes," figured prominently in the pharmacopoeia of the ancients, 

 being much esteemed as remedies for a great variety of disorders. They are largely 

 composed of carbonate and phosphate of calcium, and when the sacs in which they 

 are formed are opened each mass separates into several hundred snow-white rods or 

 columns. 



A curious habit which I have lately observed in the case of small lobsters (3 to 5 

 inches long) which have recently molted, is that of stuffing the stomach with frag- 

 ments of calcareous matter, such as weather-worn pieces of shells of mollusks. The 

 examination of the stomachs of hard-shelled lobsters of similar size has not shown 

 any such remarkable assortment of calcareous materials, and it is possible that in 

 the absence of gastroliths these are swallowed by the young lobster after each molt 

 to furnish the growing cuticular skeleton with lime. It has not yet been determined 

 at what particular period in the life-history of the lobster the gastroliths make 

 their first appearance. 



After shedding, the lobster is, for the most part, helpless, except in so far as it is 

 able to elude capture by hiding in seaweed or under stones, and must often fall a prey 

 to fish. One would suppose that they would resort to their burrows at such times, 

 but I have seen no evidence of their doing so. As shedding is the result of growth, 

 which is dependent upon a variety of conditions, molting lobsters are found at nearly 

 all times of the year. For the majority, however, the period of ecdysis is the summer 

 and fall, varying in different localities and in different years. In the eastern dis- 

 tricts of the Maine coast the greatest number of soft-shelled lobsters is taken in 

 September; in the western, in July and August. Some are occasionally caught in 

 winter, but are very rarely taken in March, April, and May. Lobsters thus, as a rule, 

 molt in shallow water, but "shedders" and "'soft shells" have been occasionally taken 

 from the stomachs of codfish caught in deep water outside, The adult lobster increases 

 its length at each molt by about 12 per cent; that is, by 1 to H inches. 



There is no definite limit as to age or size when this process can not take place, 

 since we find adult lobsters^of all sizes from the smallest to those weighing upwards 

 of 30 pounds. I have recently examined the large claw of a lobster, said to have 

 weighed when alive 39 pounds, and which must have actually weighed 28 to 30 pounds. 

 It is evident from the thinness of the shell of the claw that it belonged to an indi- 

 vidual which had molted within two months from the time of its capture. The 

 daw was 13 inches long and 174 inches in girth, while its total weight was only 16f 

 ounces, including the third joint. 



Female lobsters reach sexual maturity when 8 to 12 inches long, possibly a very 

 few when even smaller, a larger number at the length of inches, and the majority 

 when measuring 10 to 12 inches. 



