252 S. I. Smith — Early Stages of the American Lobster. 



a few observations at New Haven in May, 1872.* Eggs taken May 

 2, from lobsters captured at New London, Connecticut, had embryos 

 well advanced, as represented in figure 1. In this stage the eggs are 



slightly elongated spheroids, 



^^' ■' about 2.1""" in the longer dia- 



o -, . , , 



meter and 1.9 m the snorter. 



One side is rendered very opa- 

 que dark green by the unab- 

 sorbed yolk mass, while the 

 • other shows the eyes as two 

 large black spots, and the red 

 z pigment spots on the edge of 

 the carapax, bases of the legs, 

 etc., as irregular lines of j^ink 

 markings. 



In a side view of the embryo, 

 the lower edge of the carapax 

 {h, figure 1) is clearly defined 

 and extends in a gentle curve 

 from the middle of the eye to 

 the posterior border of the embryo. This margin of the carapax is 

 marked with dendritic spots of red pigment. The whole dorsal por- 

 tion, fully one-half the embryo, is still occupied by the unabsorbed 

 portion of the yolk (a, a, figure 1), of which the lower margin, repre- 

 sented in the figure by a dotted line, extends from close above the 

 eye in a curve nearly parallel with the lower margin of the carapax, 

 but with a sharp indentation a little way behind the eye. The eyes 

 (c, figure 1) are large, nearly round, not entirely separated from the 

 surrounding tissues, and with a central portion of l)lack pigment. 



The antennula; (c?, figure 1) are simple, sack-like appendages, aris- 

 ing from just beneath the eyes, with the terminal portion turned back- 



* The season at which the female lobsters carry eggs varies very much on different 

 parts of the coast. Lobsters from New London and Stonington, Connecticut, are with 

 eggs in April and May, while at Halifax, Nova Scotia, I found them with eggs, in which 

 the embryos were just beginning to develop, early in September. A corresponding 

 variation is noticed in the lobster of the European coast. 



•)• Embryo, some time before hatching, removed from the external envelope and 

 shown in a side view enlarged 20 diameters; a, a, dark -green yolk mass stiU unab- 

 sorbed ; 6, lateral margin of the carapax marked with many dendritic spots of red 

 pigment; c, eye ; c?, antennula; e, antenna ; /, external maxilhped ; </, great cheliped 

 which forms the big claw of the adult ; 7i, outer swimming branch or exopodus of the 

 same ; i, the four ambulatory legs with their exopodal branches ; k^ intestine ; I, heart ; 

 v/i, bilobed tail seen edgewise. 



