4fiO 



MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 



hirgest pol_vp (tig. 8'^) the tir.st two cycles of mesenteries are fully established, a pair of metaenemes 

 having appeared within each of the six primary exocceles. 



n 



Aalranffia solilaria. — Fig. 8. Series of diagrammatic figures (a-g) illustrating the order of appearance of the mesenteries of the flist and 

 second cycles of metaenemes. «, Four isocncmic pairs of the first cycle of metaenemes are present (II), while three of the protocnemes 

 are not yet united with the stomodseum. 



n 



n 



Fig. s6. 

 Aatranfjia gnlitarin. — The protocnemes are all complete, and the si.\ pairs of first-cycle metaenemes have all appeared. 



Fig. Sc presents the tirst appearance of the third-cycle mesenteries or second-cycle metaenemes. 

 which are to be especially studied. A new pair of mesenteries has appeared within the exoc(jele 



