PROTOZOA OU SIMPLEST ANIMALS. 



17 



(Plate X. ill the Case) has a Hat triauf^ular hody wiih a spine at each Hij.h Wall 

 an<^lc. The two grooves form an iiiv<rted T-shape, the vertical bar *r.^^' 

 being very broad. The presence of eiha in the transverse band in (iallerv. 

 IMate X. is incorrect, there being simply a single flagellum lying in 

 the groove. 



Ceratium is ]»hus[ihoresceiit,;uid in Lhe oiteu ueean is often funnd 

 united into chains of two to twenty individuals. 



Nodiluca miUarls (Fig. \2) is a little peach-slmped organism 

 about 3V of an inch in diameter. A thick transversely-striated 

 " big flagellum " springs from the bottom of a deep groove on one 



Fig. 13. 



VorticeUa nehuli/em, a colonial lifll-.\iiimiilcule. 

 (Maguitied.) c i', contractile vacuole. 



side of the body. Xear the groove is the mouth leading into a 

 cylindrical throat, in which is placed a second and smaller tlagcllum. 

 The body is invested by a firm cuticle, and the protuplasm in the 

 interior is vacuolated. See Plate XI. in the Case. 



Noctiluca is highly phosphorescent, the light emanating cliiefiy 

 fi'oiii the protoplasm just beneath the cuticle. 



.Marine phosphorescence is sometimes due entirely to the presence 

 <»f myriads of Xdr/ilifnr, which may be present in such al)undauce 



