48 



ZOOLOGY 



SECT. 



from a cyst in having an aperture at one end to allow of the 

 protrusion of pseudopods from a small naked area. This is exactly 

 what we find in Arcella and its allies (Fig. 29, A-c), in which the 

 shell is chitinoid. A different kind of shell is found in Difflugia 

 (D), which secretes a gelatinous coating to which minute sand- 

 grains and other foreign particles become attached. 



V lj$M/liL 



A ^ 



FIG. 30. Chlamydomyxa labyrinthuloides. A, active phase; c.w. ceU-wall; /. frag- 

 ment of Alga ingested as food ; sp. spindles in course of pseudopods ; B, resting stage 

 numerous individuals in the cells of a fragment of Sphagnum; a, specimen completely enclosed 

 in cell ; It and <-, specimens which have emerged through the ruptured cell-wall ; C, specimen 

 multiplying by budding ; D, by binary fission ; E, by internal fission. (A after Archer, B E 

 after Geddes.) 



ORDER 2. LABYRINTHULIDEA. 



In this group there are only two genera Labyrinthula and Chlamydomyxa. 



Chlamydomyxa (Fig. 30) has hitherto been found only in Ireland, where it 



occurs in association with the common Bog-moss (Sphagnum). Like Amoeba, it 



