EMBRYOLOGY OF CTENOPHORffi. 



35 



than that of the other Ctenophorae. Pigs. 34, 35, and 36 show 

 the Pleurobrachia at Yarious stages of growth ; Fig. 34, with its 

 thick stunted tentacles and short rows of flappers, is the youngest ; 

 the flappers themselves are rather long at this age, looking more 

 like stifiT hairs than like the minute fiinges of the adult. In Fig. 



Fig. 34. Fig. 36. 



35 the tentacles are already considerably longer and more deli- 

 cate ; in Fig. 36 the vertical «tubes are already completed, while 

 Figs. 27 - 29 present it in its adult condition. 



The Idyia differs greatly in appearance at different periods of 



Fig. 80. Fig. ST. 



its development, and, indeed, no one would suspect, without some 

 previous knowledge of its transformations, that the young Idyia, 



Fig. 34. Toung Pleurobrachia still in the egg ; ( tentacles, e eye-speck, e c raws of locomotire flap- 

 pers, d digestive cavity; greatly magnified. 



Fig. 36. Young Pleurobrachia swimming about In the egg just before batching ; magnified. 



Fig. 36. Toung Pleurobrachia resembling somewhat the adult ; /funnel leading to anal opening, I 

 lateral tubes, cec'c* rows of locomotive flappers; magnified. 



Fig. 37. Toung Idyia, greatly magnified ; lettering as in Fig. 36 ; d digestive cavity. 



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