372 iS. I. SinitJi — Early Stages of the Ainerican Lobster. 



the terminal segment being broad, flattened, clothed with numerous 

 setse, and acting within the edges of the crowns as in the adult. 



The first maxillre (plate XVI, fig. 3, enlarged 20 diameters) have 

 the proximal lobe (fig. 3, a) of the endognathus rounded at the ex- 

 tremity as in the adult but with much fewer setse, while the distal 

 lobe (fig. 3, b) is not expanded at the end as in the adult and, like the 

 proximal lobe, has fewer setae. The exognathus (fig. 3, c) is composed 

 of two segments as in the adult, but the terminal segment is much 

 shorter than the other, nearly straight, and naked to the extremity, 

 which is tipped with three setae of dififerent lengths, while in the 

 adult this terminal segment is as long as the basal, curved sinuously 

 backward and outward, is ciliated along the inner or anterior margin, 

 and tipped with numerous setoe. 



The second maxillje (plate XVI, fig. 5, enlarged 20 diameters) difter 

 but slightly from those of the adult. The anterior of the four lobes 

 (fig. 5, a) of the endognathus is rounded at the extremity, while in the 

 adult it is subtruncate, and the extremities of all the lobes are armed 

 with fewer setae than in the adult. The exognathus (fig. 5, b) is rela- 

 tively longer than in the adult, but is furnished with only a few hairs, 

 while in the adult it is thickly ciliated along the inner edge and at 

 the tip. The epignathus (fig. 6, c) is relatively a little smaller than 

 in the adult. 



In the first maxillipeds (plate XVI, fig. 8, enlarged 20 diameters) 

 the endogathus (fig. 8, a) is slightly narrower than in the adult and 

 has fewer marginal setae. The terminal segment of the mesognathus 

 (fig. 8, b) is narrow, tapers to an obtuse extremity and has but a very 

 few mai'ginal cilia, while in the adult it is ovate in outline and closely 

 fringed witli cilia. The exognathus (fig. 8, c) is a little shorter than 

 in the adult, and the terminal flagelliform portion is composed of a 

 few (seven or eight) segments as long as broad and furnished at the 

 distal ends with long plumose hairs, while in the adult the segments 

 are very short and numerous and the hairs quite short. The epigna- 

 thus is not prolonged })osteriorly into so long and slender a point as 

 it is in the adult. 



In the second maxillipeds (plate XVI, fig. 12, enlarged 20 diame- 

 ters) the endognathiis is only sparsely armed with spines and setae, 

 while in the adult it is thickly beset with them. Tlie exognathus 

 (fig. 12, a) is nearly as long as in the adult, but the flagelliform portion 

 difiers, as the same part in the first maxillipeds, in being composed 

 of few segments with long plumose hairs, while in the adult the seg- 

 ments arc very numerous and the hairs short. The epignathus (fig. 1 2, 

 b) is much shorter than in the adult and the branchial appendage 



