250 



ZOOLOGY 



at 



FIG. 236. -- Ciona, a simple 

 tunicate, o, mouth ; at, open- 

 ing of atrium, or exhalant 

 opening; st, stolon. After 

 Leuckart aud Nitclie's dia- 

 grams. 



FIG. 238. - - Balanoglossus, the acorn- 

 tongued worm. The proboscis at the 

 anterior end is at the top of the figure 

 (partly outside) ; behind it is an 

 orange-colored collar: then follows 

 the long, brown-red trunk. Nat. size. 

 Photo, of living animal by W. H. C. P. 



FIG. 237. Botryllus, a compound tunicate. Nat. size. Photo, by W. H. C. P. 



