S. I. Smith— Early Star/es of the American Lobster. 363 



The ocular peduncles are slightly longer and less stout in propor- 

 tion than in the first stage, and the cornea is not quite as broad. 



The antennulffi (plate XV, fig. 8, enlarged 20 diameters) are pro- 

 portionately no larger than in the last stage, but the three segments of 

 the peduncle are distinctly defined and the flagella are separated down 

 to the peduncle. The primary, or outer, flagellum is as short as the 

 peduncle, indistinctly divided into about six segments, and the inner 

 side furnished, especially toward the distal extremity, with many 

 cylindrical, and apparently tubular, hairs, which are half as long as 

 the flagellum itself and truncated at tip. The secondary, or inner, 

 flagellum is slender, about a third the diameter of the primary, and 

 considerably shorter, shows no division into segments, and is furnished 

 with one long and one very short cilium at tip. The distal segment 

 of the peduncle bears, near the base of the secondary flagellum, a 

 single, long, sparsely ciliated hair, perhaps auditory in its function, but 

 no other indication of auditory apparatus connected with the pedun- 

 cle was discovered. 



The antemife are as in the first stage, except that the flagella are 

 almost as long as the scales, and in all the specimens examined are 

 without the long hairs at the tips. 



The mandibles are as in the first stage, except that they are perhaps 

 slightly more indurated and the segments of the palpi more distinctly 

 indicated. 



In the first maxilla?, the spines and setae upon the lobes of the 

 endognathus have increased slightly in number and size. The ex- 

 ognathus is proportionally somewhat longer and has an additional 

 seta at the tip, so that there are three terminal ones increasing in 

 length from the outside; while the large one upon the inside arises 

 somewhat further from the tip. 



In the second maxillae, the lobes of the endognathus and the ex- 

 ognathus are as in the first stage, except a slight increase in the num- 

 ber and size of the spines upon the lobes of the endognathus. The 

 posterior portion of the epignathus has increased considerably in 

 length and is much broader than the anterior portion. 



The first, or inner, maxillipeds difier only very slightly from those 

 in the first stage. The mesognathus is relatively of the same size 

 and is furnished with the same number of setae. The exognathus is 

 slightly longer in proportion and the posterior portion of the epigna- 

 thus is proportionally larger than the anterior portion. 



In the second maxillipeds the endognathus has changed very little 

 from the first stage, the proportions of the segments and the number 



Trans. Connecticut Acad., Vol. II. 30 August, 1873. 



