Dinobryacew 



47 



Genus Syncrypta Ehrenb., 1838. This is a motile colony 

 similar in appearance to Synura but invested with a mucilaginous 

 coat through which the cilia protrude. 



Syncrypta Volvox Ehrenb. is an abundant organism which bears great 

 resemblance to Synurct Uctfla. 



Genus Uroglena Ehrenb., 1838. In this colonial form tin- 

 cells are of the same nature as those of Synura, but the central 

 portion of the colony is a hollow space filled with mucilage, and 

 the ciliated cells are arranged round the periphery. 



Volcox Ehrenb. is found in similar situations to those mentioned 



t/ 



for the two previous genera. It is, however, much less abundant. 



Family 3. DINOBRYACE.E. 



The individuals are attached to the bottom of a cup-shaped 

 receptacle, which is widely 

 open above. They are con- 

 tractile and possess two cilia 

 of unequal length. 



Genus Dinobryon Ehr., 

 1833. The cells are very 

 delicate, of a somewhat 

 changeable form, and are 

 sensitive to stimuli. The 

 lower end is attenuated into 

 a stalk which is attached 

 near the base of the open 

 receptacle. There is one 

 long cilium and one shorter 

 secondary cilium. The chro- 

 matophores are two in num- 

 ber and of a yellow -brown 

 colour. There is a pigment 

 spot,two contractile vacuoles, 

 and one cell-nucleus. The 

 receptacle is campanulate or 

 cylindrical, attenuated at its 

 lower end into a straight or 

 oblique point; it is hyaline or sometimes coloured yellow or bn>\vn 



Fig. 7. A, Dinobryon cyliiuJricum Iinhof 

 var. dirertjcnit Lemm.; two living examples 

 from Eldwick, W. Yorks. ( x 730). B, en- 

 cysted condition of same. C, Dinnliri/nn 

 S/Ttularia- Ehrenb., colony with individuals 

 encysted, from Cornwall ( x410); c, cysts. 



