EXPLANATION OF PLATE XII. 



FIG. 



1-4. PHALANSTERIUM DIGITATUM, St. (after Stein). i, Adult branching mucila- 

 ginous zoocytium, x 450 ; 2-3, early conditions of a similar zoocytium ; 

 4, a single animalcule, X 1 200 ; d, rudimentary collar. 



5-9. PHALANSTERIUM CONSOCIATUM, Cienk. 5, Adult discoidal colony, x 650 (after 

 Stein) ; 6, an isolated animalcule further enlarged ; 7 and 8, encysted zooids 

 (after Cienkowski), the one at Fig. 8 having developed a hard tricarinate 

 capsule ; 9, an animalcule dividing by longitudinal fission. 

 10. SPONGOMONAS DISCUS, St., x 650 (after Stein). 



11-14. SPONGOMONAS INTESTINUM, Cienk. sp. 11, Filamentous adult colony, natural 

 size (Cienk.) ; 12, extremity of similar colony enlarged, showing disposition 

 of contained animalcules ; 13, an isolated monad, x 650 ; 14, fragment of 

 gelatinous granular zoocytium, showing at a normal zooid ; S, two zooids 

 derived from the longitudinal fission of such as a ; c, a retracted and encysted 

 zooid ; d, e, f, various multiplicative phases by which a primary quiescent 

 or encysted zooid has become divided into two, four, or eight spore-like 

 bodies, X 650 (12-13 after Stein). 



15, 16. SPONGOMONAS UVELLA, St. (Stein). 15, An adult colony, x 650; 16, initial 

 condition of such a colony as founded by a single animalcule. 



17-23. SPONGOMONAS SACCULUS, S. K. 17, Adult colony, x 10; 18 and 19, showing 

 proportionate growth of same colony in three days as observed by the author, 

 natural size ; 20, fragment of granular zoocytium, containing two normal 

 biflagellate and a single encysted subdividing zooid, x 1200 ; 21 and 22, 

 isolated zooids, x 1200 ; 23, encysted zooid dividing by transverse fission. 



