EXPLANATION OF PLATE XIII. (continued). 

 FIG. 



54. PLATYTHECA MICROPORA, St. Three loricae with their contained animalcules 

 attached to a joint of conferva ; at a two zooids, the result of fission, 

 occupy the same lorica, x 650 (Stein). 



55-64. OIKOMONAS MUTABILIS, S. K. 55, A group of four monads attached to vegetable 

 fibre, showing at a and b normal sedentary forms, at c an example ingesting 

 food-matter at its lateral periphery, and at d a young and recently adherent 

 example, not having yet developed a filiform pedicle, x 800 ; 56, an adult 

 monad about to exchange its sedentary for a free-swimming condition ; 

 57, the same monad detached and free-swimming, still retaining an attenua- 

 tion of its posterior and previously fixed extremity ; 58, typical free-swimming 

 zooid ; 59 and 60, more aberrant forms ; 61, a motile zooid dividing by 

 longitudinal fission ; 62 and 63, spore-masses produced by segmentation of 

 encysted animalcules ; 64, a young monad developed from a spore. 



65-70. OIKOMONAS STEINII (S. K.) 65, A group of monads attached to a spheroidal 

 bacterial mass, X 650 ; 66, four monads similarly attached, exhibiting a 

 considerable irregularity of contour ; 67, a free-swimming animalcule with 

 branched posterior extremity ; 68, a free-swimming animalcule dividing by 

 transverse fission ; 69 and 70, young free-swimming monads (Stein). 



71. OIKOMONAS QUADRATUM, S. K. A group of five monads ; at a and b, zooids 



ingesting food at opposite regions of the periphery, x 800. 



72. OIKOMONAS OBLIQUUS, S. K., filled with artificially administered carmine- 



particles, a portion of which it is discharging from its posterior extremity, 

 x 2500. 



73-77- OIKOMONAS ROSTRATUM, S. K. 73, A group of monads attached to a vegetable- 

 fibre, x 800 ; 74 and 75, two attached monads, the one with and the other 

 without a posteriorly developed pedicle, x 1000 ; 76, an example with an 

 abnormally long pedicle ; 77, a free-swimming monad with pedicle retracted. 



78-80. OIKOMONAS TERMO, J.-Clark sp. 78, A group attached to vegetable fibre, 

 showing at a a zooid dividing by longitudinal fission, at b an example ingesting 

 food-matter, and at c a young, recently attached and almost stalkless zooid, 

 x loco ; 79, a free-swimming monad ; 80, a free-swimming zooid dividing by 

 fission. 



