/S. J. Smith — Early Stages of the American Lobster. 3V3 



(fig. 12, c) is obtuse at the tip and has only a few lobes in the margin, 

 while in the adult it is slender at the tip and is made up of numerous 

 slender papillae. 



The endognathus of the external maxillipeds (plate XVI, fig. 14, 

 enlarged 10 diameters) has nearly the same form and proportions as 

 in the adult, but is furnished with fewer and. longer seta3, and the 

 teeth upon the inner angle of the ischium are fewer and more acute. 

 The exognathus (fig. 14, a) is relatively no longer than in the adult, 

 but the flagelliform portion is composed of fewer segments and is 

 furnished with much longer plumose seta?. The epignatlius (fig. 14, h) 

 is much shorter than in the adult, and is not prolonged as there into 

 a long and slender extremity. The three branchial appendages (fig. 

 14, c) are proportionally shorter and more obtuse than in the adult, 

 and have comparatively few and short papillae. 



The anterior cephalothoracic legs (plate XVII, fig. 12, terminal 

 portion of the right one, enlarged 10 diameters) are alike on the two 

 sides, are considerably longer than the carapax to the tip of the ros- 

 trum, and are formed much like the smaller one in the adult, although 

 considerably more slender and wanting the stout teeth upon the 

 upper edge of the basal portion of the propodus. 



The legs of the second and third pairs (plate XVII, figs. 4, and 

 4«, one of the second pair, enlarged 20 diameters) are of the same 

 form and proportions as in the adult, but are armed with fewer and 

 I'elatively longer spines and setae. 



The legs of the posterior and penultimate pairs (plate XVII, fig. 8, 

 terminal portion of one of the posterior pair, enlarged 20 diameters), as 

 well as those of the second and third pairs, are like those of the adult 

 in form and proportions, but are armed with fewer spines and setae. 



The abdomen (plate XVIII, fig. 10, side view of the second to fifth 

 segments, enlarged 8 diameters, and fig. 4, telson with the appendages 

 of the penultimate segment on one side, enlarged 20 diameters) is 

 scarcely as long as the cephalothorax, including the I'ostrum, while in 

 the adult it is considerably longer. The lateral angles of the second, 

 third, fourth, and fifth segments are prolonged downward into long 

 and acute teeth, and the second segment is similar to the following 

 ones and overlaps the first segment scarcely at all. In the full-grown 

 adult, the sides of the second segment are broad, overlap the first 

 segment, and are truncated beloAv with the anterior angle rounded 

 and the posterior right-angled, while the sides of the third, fourth, 

 and fifth segments are narrow and have the postero-lateral angles 

 projecting backward in a slight tooth. No ai)pendages could be 

 found upon the first segment. The natatory legs of the second, third, 



