542 THE AXATOMY OF INVERTEBRATED ANIMALS. 



Thus far, although the organization of Sagitta is very 

 peculiar, it presents analogies both with the Nematoidea and 

 with the Annelida, But its development, as described by 



\—,0—^a 



"i 



\u% 



Fig. \^^,—SaQitta Mpiinctata.—a, the head, with its eyes and appenda2:c8 ; ft, the 

 anus ; c, the ovary ; d, iho testicular chambers. 



Kowalewsky,* is, in some respects, unlike anything at pres- 

 ent known in either of these groups. Yelk-division takes 

 place as usual, and converts the eggs into a vesicular morula, 



^ " M^moires de 1' Academic Imperiale des Sciences de St.-Pctersbourff," 



1871. 



