105 



slender spines; hut no truces of tin- Intend spinules have MS yet appeared, nor 

 do the uropoda (urp) as yet exhibit any armature whatever. No trace of cal- 

 careous matter lias as yet been deposited in the integuments, which of course 

 are very thin and pellucid, admitting the inner organs to be traced with great. 

 distinctness through their walls. The stomach (st) has assumed its characteristic 

 form and curvature, and all 3 liver-sacs (1) on each side have been formed; but 

 the upper and lower sac are still very short, scarcely attaining half the lenght of 

 the middle one. Behind the carapace dorsally, the heart (h) is easily observable, 

 as also the renal organs (n) occurring to each side of it. The intestinal tube 

 is still without any contents, and on this account is less conspicuous than in the 

 post-embryonal stages. 



When the young is ready to escape from the mother, it has assumed 

 much the appearance of the adult animal, and the integuments have been partly 

 indurated with calcareous deposits, so as to make them rather hard and intrans- 

 parent. The only essential difference consists in the absence of the last pair of 

 legs. On a closer examination, however, these limbs are found in process of 

 development, but enclosed within a conspicuous ventral prominence of the last 

 trunk segment. They will accordingly be set free by a subsequent exuviation. 



