146 



PROTOZOOLOGY 



Catenoid or linear colony. The daughter individuals are attached 

 endwise, forming a chain of several individuals. It is of compara- 

 tively rare occurrence. Examples: Astomatous ciliates such as 

 Radiophrya (Fig. 266), Protoradiophrya (Fig. 266) and dinoflagel- 

 lates such as Ceratium, Haplozoon (Fig. 109) and Polykrikos (Fig. 

 110). 



Arboroid or dendritic colony. The individuals remain connected 

 with one another in a tree-form. The attachment may be by means 



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Fig. 68. a, b, budding in Myxidium lieberkuhni; c, d, plasmotomy in 

 Chloromijxum leydigi; e, plasmotomy in Syhaeromyxa balbianii. 



of the lorica, stalk, or gelatinous secretions. It is a very common 

 colony found in different groups. Examples: Dinobryon (Fig. 92), 

 Hyalobryon (Fig. 92), etc. (connection by lorica); Colacium (Fig. 

 102), many Peritricha (Figs. 322; 324), etc. (by stalk); Poterioden- 

 dron (Fig. 116), Stylobryon (Fig. 130), etc. (by lorica and stalk); 

 Hydrurus (Fig. 93), Spongomonas (Fig. 129), Cladomonas (Fig. 129) 

 and Anthophysis (Fig. 130) (by gelatinous secretions). 



Discoid colony. A small number of individuals are arranged in a 

 single plane and grouped together by a gelatinous substance. Exam- 



