54 



X AT URAL HISTORY OF ARTHROPODS. 



bun the following statistics : In 1880 the total catch on the Maine coast amounted to 



~ 



14,234,000 pounds, valued at $268,000, fishermen's prices ; in Massachusetts 4,315,000 

 pounds, valued at $158,000. Of the Maine catch the larger proportion was canned, 

 the twenty-three canning establishments in that State taking about 9,500,000 pounds ; 

 while the Provincial factories put up an even larger amount. The quantity of lobsters 

 handled by the several large fresh markets during 1880 was as follows: Boston, 

 3,637,000 pounds ; New York, '2,500,000 pounds, and Portland, 2,000,000 pounds. 



All of the interested States, with the exception of New Jersey, have passed more or 

 less stringent laws regulating the time of catching and the size of the lobsters caught, 

 those of Maine being the most lax. For several years past the average size of the 

 lobsters caught has been decreasuig, a specimen weighing four pounds being compara- 

 tively rare. Lobsters, however, are occasionally found much larger in size, there being 

 one in the Museum of the Peabody Academy of Science at Salem, Mass., which 

 weighed thirty-nine pounds. 



The lobster, when about to moult, seeks some secluded spot under the shelter of a 

 large stone, and there sheds his old shell. As a preparation for this act the lime salts 

 in certain parts of the integument are absorbed, and then the carapax splits down the 

 back, and through this opening the animal withdraws itself. As it would be impos- 

 sible for the enormously developed claws to pass through the rigid joints of the arm, 

 there is an absorption of the lime salts in these joints, and thus the claw is readily 

 withdrawn. Together with the old shell, the lobster, like all Crustacea, sheds the lin- 

 ing of the stomach and of the posterior portion of the intestine. After moulting the 

 lobster's skin is very soft, and the flesh soon becomes poor, watery, and flabby ; but in 

 a short time, by a deposition of calcic carbonates and phosphates, the new integument, 

 which is larger than the old one, regains its former firmness, and in a few days the 

 flesh acquires its former solidity and indigestibility. 



The breeding season varies according to 



the locality. In Long Island Sound the eggs 

 are laid sometimes as early as the last of 

 April or the first of May. In Massachusetts 

 Bav the season extends from about the first 



/ 



of June to the first of August, w T hile Pro- 

 fessor S. I. Smith found at Halifax females 

 with newly-laid eggs in September. For a 

 knowledge of the development of our lobster 

 we are indebted to Professor Sydney I. Smith, 

 Mr. G. O. Sars having performed a similar 

 work for the European species. The eggs, 

 which for Crustacea are very large, are of a 

 dark green color, and at the time of hatching, 

 the embryo strongly resembles a My sis, all 

 of the thoracic feet being two-branched, while 

 the external maxillipeds play a part in loco- 

 motion. At the next stage the abdominal feet appear, and at each succeeding 

 moult the young approaches more nearly the adult, retaining, however, their free- 

 swimming habits until about half an inch in length. 



The LORICATA differ anatomically from the group we have just left, by the 

 absence of a scale on the basal joint of the antennae, and in having the anterior pair of 



FIG. 64. Embryo lobster some time before hatch- 

 ing, natural size above, o. Yolk. b. Margin 

 of carapax. c. Eye. </. Antemmla. e. \n- 

 teniia. (j to i. Thoracic feet. k. Intestine. /. 

 Heart, m. Telsou. 



