Fis. I. 



Introduction to Animal Morphotogy. 49 



This sub-kingdom includes eight classes, which 

 form two diverging series.* 



Class i. M.O'^'K^K {Hacckcl). — The simplest living 

 beings ; organless, aquatic cytodes with pseudopodia ; 

 rounded when resting or starved, irregular otherwise ; 

 reproduction asexual. 



There are two orders of these : — ist. Gymnomonera, with 

 no resting stage nor capsule, reproducing by fission. They 

 may be single, non-vacuolated with simple (Protamoeba,f 

 Fig. I, A) or branched pseudo- 

 podia (Protogenes|), or united 

 in clusters by netted processes 

 (Myxodictyon), or in vacuolated 

 masses with irregular pseudo- 

 podia, found at great depths in 

 the Atlantic Ocean(Bathybius§). 

 2nd. Lepomonera, with a rest- 

 ing stage in which the body 

 becomes surrounded by a cap- 

 sule, and the interior breaks up into flagellate spores, which 

 on emission become like the parent. This includes Proto- 

 monas, a non-vacuolated form found in decaying Nitella 

 stems ; Protomyxa, marine, in its resting stage a round orange 

 ball, whose contents break up into tailed spores, becoming 

 vacuolated amoeboid cytodes with branched pseudopodia ; 

 two or three of these coalesce to form a mass like the parent. || 

 Vampyrella is non-vacuolated, and reproduces by tetraplasts, 

 round masses at first dividing into two, then into four, &c. 

 Each of these becomes rounded with radiating processes : 

 they are parasitic on Algag (three freshwater and one marine 



* Monera, RMzopoda, Heliozoa lead us through Radiolaria to Porifera ; 

 Flagellata, through PeridiniDsa and Infusoria, lead us to Turbellaria. 

 t Two marine and three freshwater species. 

 X One marine species. 

 § Doubtful. 

 II This form may be propagated by artificial di\-ision. 



Magospliajra planula. 



Protamoeba. 



priraitiva. 



