S. I. Smith — Early Stages of the Aineruxai Lobster. 257 



animal) the other edge, as a stout lamelliform process. This process 

 is quite different in the two mandibles. In the left (fig. 14, a) its 

 posterior margin is separated from the body of the mandible for 

 quite a distance, and its inner, or terminal, edge divided into three 

 irregular obtxise teeth, of which the posterior is most prominent ; 

 while on the right side this process is separated only for a short dis- 

 tance, the teeth are quite different in form, and the posterior one is 

 the least prominent. 



In the first pair of maxillae (plate XVI, fig. 1, enlarged 40 diame- 

 ters) the endognathus is composed, as in the adult, of two lobes (fig, 

 1, a, h), the proximal lobe [a) rounded at tip and margined with 

 scattered setiform spinules, the distal lobe (/>) truncated at the ex- 

 tremity, which is armed, somewhat as in the adult, with closely set 

 acute spinules. The exognathus (fig. 1, c) is much shorter than the 

 endognathus, is composed of a single article, and is armed at and near 

 the distal extremity with four seta (fig. 1«, enlarged 100 diameters), 

 of which two are at the tip, the inner one about as long as the 

 exognathus itself, the outer a little shorter ; another, aboiit as long as 

 this last, arises from an emargination on the inside a little way from 

 the tip ; while the fourth arises near the base of the inner one and is 

 very small. 



In the second pair of maxillse (plate XVI, fig. 4, enlarged 40 dia- 

 meters) the four lobes of the endognathus («) are proportionally 

 much shorter than in the adult, the tips are broadly and evenly 

 rounded and sparcely armed with stout and simple set£e. The 

 exognathus (fig. 4, b) is short, scarcely reaching to the tip of the 

 outer lobe of the endognathus. It is naked nearly to the tip, which 

 is armed with six simple seta-. Three of these setoe are at the very 

 tip (fig. 4a, enlarged 100 diameters), the inner and longest one 

 equalling in length the body of the exognathus itself, the middle one 

 somewhat shorter, and the outer very small ; two others, as long as 

 the middle one of the tip, arise together from an emargination upon 

 the inner side near the extremity ; while another starts from just 

 below the bases of these, but is only half as long as they. The an- 

 terior portion of the e})ignathus (fig. 4, c) is about as long and slightly 

 broader than the outer lobe of the endognathus, while the posterior 

 portion is quite small, but little larger than the anterior. The edge 

 of the epignathus is furnished all round with rather stout, jointed, 

 and densely plumose hairs. 



The first, or inner, maxillipeds (plate XVI, fig. 6, enlarged 40 dia- 

 meters) differ from those of the adult chiefly in being more rudimen- 



