XIII. — The Early Stages of the American Lobster {Ilomanis 

 Americanus Edwards). By Sidney I. Smith.* 



A great part of the published observations on the early history of 

 the higher Crustacea has been confined to the changes which take 

 place in the embryo within the egg or immediately after leaving it. 

 Of the later stages, which connect the newly hatched young with the 

 adult, very little is known, even in species of which the embryology 

 proper has been considerably studied. This results naturally from the 

 great difticulty of rearing the young of these animals in confinement. 

 In fact, it is usually easier to obtain the young in the differ&nt stages 

 directly from their native haunts, as has been so successfully done for 

 some of the radiates and worms by Alexander Agassiz, than to at- 

 tempt to rear them in ordinary vessels or small aquaria. In the case 

 of many of the higher Crustacea, a part of the early history might 

 often be traced back from the adult more easily than it can be from 

 the Qgg up. 



The following account of the development of the American lobster 

 during its fi-ee-swimming stages is one of the results of the facilities 

 for collecting and studying the marine animals of Vineyard Sound, 

 Buzzard's Bay and the adjacent region, aflTorded me during the sum- 

 mer of 18Y1, by Professor Spencer F. Baird, United States Commis- 

 sioner of Fish and Fisheries. 



Numerous specimens of the free-swimming young of the lobster, in 

 difierent stages of growth, were obtained in Vineyard Sound, but my 

 time while there was so fully occupied in collecting that little was 

 left for studying the animals while alive. The figures and descriptions 

 which follow — except a few notes on color — have consequently all 

 been made from specimens preserved in alcohol, so that this article is 

 confined almost wholly to the development of the tegumentary ap- 

 pendages and does not include a study of the anatomy of the soft 

 internal organs. 



As no opportunities were ofiered in 1871 for observations upon the 

 young within the egg, this deficiency has been partially supplied by 



* A brief abstract of a part of this paper, with the figures on plate XIV, appeared 

 in the American Journal of Science, 3d series, vol. iii, p. 1, June, 1872. A short notice 

 of it is also inserted in an article on " The Metamorphoses of the Lobster and other 

 Crustacea," in the Report of the tT. S. Commissioner of Fish and Fisheries on the Con- 

 dition of the Sea Fisheries of the Soutliern Coast of New England in 1871 and 1872, 

 p. 522, 1873. 



