THE GLASS-CRABS OR PHYLLOSOMATA. 



307 



79, -5), had gradually in the pupa (Fig. 79, F^ G) assumed 

 the opposite curvature. Its dimensions are threefold those 

 of the embryo, and it exhibits vivacious movements when ex- 

 tracted from the pouch of the parent. It is not improbable 

 it may yet undergo another change of integument before ac- 

 quiring the full form of the adult. 



Thus it appears that, in Mysis, the JVaitpli us -stage (Fig. 

 79, J), E) is passed over so rapidly that the embryo has gone 

 through it at a very early period, and nothing but the cuticu- 

 lar sheath of the body appertaining to this stage remains to 

 prove its existence. A step further, in the abbreviation of 

 the Haii2:)Uus-stage, and there would be nothing to distin- 



// n 



Fig. m.—Phyllosoma.—A, ventral view of flie body, with the limbs P-XX' of the 

 left side and the bases only of XF to XIIP represented. B. side view of the 

 body. (7, the nervous system, Z>, the last cephalic and first and second thoracic 

 limbs. 



guish the general course of the development of Mj/sis from 

 that of Astacus. On the other hand, another Schizopod, 

 Eaphaiisia^ has been shown by Metschnikoff * to leave the 

 Qgg as a true Kauplius, 



» Zeitschrift /ixr wiss. Zool.^ 1871. 



