INVERTEBRATES 
Cestoda. 
The tape-worms are internal parasites of verte- 
brates. Their larvae (cysticerci or bladder-worms) 
are parasites of other vertebrates or of invertebrates. 
Dr. E. M. Walker has given me the following list 
of species that are found here. It is merely a begin- 
ning. 
Dipylidium caninum (L.)—in the Dog and Cat 
(adult). 
Taenia serrata Goeze—in the Rabbit (cysticercus). 
“  saginata Goeze—in Man (adult). 
echinococcus v. Sieb.—in Man (cysticercus). 
serialis (Gerv.)—in the Rabbit (cysticer- 
cus). 
cc 
“ 
CoELENTERATA. 
Our only representative of this group that con- 
tains so very many marine species is the well-known 
Hydra, that has been the subject of such a large 
number of experiments in regeneration. 
Hydra viridissima Pallas—(Dr. E. M. Walker). 
“  polypus L.—Sunnyside. 
oligactis Pallas—Michigan.* 
vulgaris Pallas—Michigan.* 
“ 
“cs 
PoriFera. 
Our fresh-water sponges are few in kinds, but 
often grow in great luxuriance. 
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