BULLETIN OF THE UNITED STATES FISH COMMISSION. 29 



Embryo lobsters are seldom seen at the surface in the open waters 

 about our coast and have rarely been taken in the towing net. Prof. 

 S. I. Smith, who has studied the younger stages, obtained his speci- 

 mens during July, mainly in Vineyard Sound, near Wood's Holl, Mass. 

 jS^othing positive" is known respecting the habits of lobsters during the 

 spawning season. It has been stated with reference to lobsters mar- 

 keted in Boston, that berried lobsters are seldom seen measuring less 

 tliau about lOi inches in length, and it is probable that they rarely be- 

 gin to spawn before attaining that size. However, a few smaller ones 

 were ol)8erved at Wood's Holl during the summer of 1885. In a lot of 

 fifty-two berried lobsters, examined at that i)lace in September, three 

 measured less than 10 inches, the smallest having been 9^ inches long; 

 eight were between 10 and 10| inches; ten between 10 J and 11 inches; 

 fifteen between 11 and 12 inches; eleven between 12 and 13 inches, and 

 five between 13 and 14 inches. The measurements were made from the 

 tip of the rostrum to the end of the telson, not including the hairs. 



The development of the younger stages of lobsters has been studied 

 by Prof. S. I. Smith, for the American species, and by Prof. G. O. S{irs,for 

 the European. The eggs, when first emitted, are entirely opaque and 

 of a dark green color, sometimes almost black. Professor Smith exam- 

 ined the well advanced eggs at Wood's Holl, in May. They were not per- 

 fectly round, measuring a trifle more than two millimeters (about one- 

 twelfth of an inch) in their longest diameter. One side was still dark, 

 due to the unabsorbed yelk mass, and the other more or less transpar- 

 ent, showing the eyes as two large black spots, and the outlines of the 

 carapax and legs. All of these features are readily made out under a 

 low-power objective. Soon after hatching they measure about one third 

 of an inch in length, and resemble in appearance and structure a low 

 group of shrimps, called the Schizopods, which are common on some 

 portions of our coast. The eyes are bright blue, while j)ortions of the 

 body and its appendages are marked with orange of different intensities, 

 rendering them very conspicuous objects. The swimmerets are not yet 

 develoj^ed. In the second stage, which resembles the first, they have in. 

 creased somewhat in size, and have obtained the rudiments of a portion 

 of the swimmerets. In the third stage they measure about half an inch 

 long, and the shell has become firmer than before. In the next and last 

 stage observed, the embryo is about three-fifths of an inch long ; it has 

 lost all of the characters in which it resembles the Schizopods, and has 

 assumed the more important features of the adult. It still retains the 

 free-swimming habit and is very active in its movements, frequently 

 jumping out of the water by means of its caudal appendages. This 

 stage was frequently taken from the 8th to the 20th of July, and Pro- 

 fessor Smith thinks that the larva passes through all of these stages in 

 the course of a single season. The stages immediately following the 

 above were not observed. 



