186 



BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



The eye is not fully formed in the embryo we have. In the adult 

 solitary individuals (fig. 144) it has the usual horseshoe form, except 

 that the horns of the horseshoe are parallel 

 and straight instead of curved. 



In the adult solitary individual the eleo- 

 blast has disappeared with the placenta, and the 

 intestinal " nucleus" drops down, allowing the 

 atrical siphon to extend more backward instead 

 of upward, the form of the body resembling 

 that of Apsteinia punctata (fig. 49, p. 72). 



Fig. 144.— Apsteinia asym- 

 metrica, solitary form. 

 Dorsal view of the gang- 

 lion AND EYE OF AN ADULT. 

 X 11" DIAMETERS. 



APSTEINIA ASYMMETRIC A, aggregated form. 



The adult aggregated zooids in our material 

 are so soft and collapsed that one can not 

 determine the normal form of the body. Therefore no drawings of 



U.2t3 



*i.m>. 



H J 



Fig. 145.— Apsteinia asymmetrica, aggregated form. Immature zooid still attached to the 

 stolon: A: dorsal view; B: ventral view. X 63J diameters. 



the adult are here included. There are, however, some excellently 

 preserved young zooids still attached to the stolon. All of the 



