Archer — On Cklamydomijxa Labyrinthuloiden. 159 



particulars as to its development. The nearest site at which I know 

 it to occur is some sixty miles from Dublin; but I am inclined to sup- 

 pose it will not turn out to be very uncommon; and at other seasons, 

 or other localities, to other observers, it may unfold more of its history 

 and afford fuj'ther data, to throw a light on its true nature. 



Ad interim, it may perhaps be well to epitomise its description, 

 without attempting to refer it to any special class or order for the 

 present, under the name of 



Chlamydomyxa lahyrinthuloides, n. g. et sp. 



Generic characters : — 



Body substance enclosed in a multilaminated cellulose envelope, 

 whence, thi-ough an apparently lacerated aperture, the non-nucleated 

 granule-bearing protoplasmic contents now and again emerge, iiTCgu- 

 larly giving off at the same time in an arborescent manner gradually 

 tapering ramifications, and emitting numerous extremely slender 

 hyaline ramifying threads (''filamentary tracks"), occasionally coa- 

 lescing and forming a more or less complex '' labyrinth," along which 

 proceed from the central mass (as from a reservou') numerous little 

 therein pre-existent, non-nucleated globular, but plastic, bodies, which 

 during progTession assume a fusiform figiire (" spindles"). 



Specific characters : — 



Very variable in dimensions, in an early stage endoparasitic, that 

 is, living within the tissues of aquatic plants ; general mass, with or 

 without subdivision, becoming periodically repeatedly encysted ; en- 

 veloping coat hyaline, glossy, of a pale, yellowish colour, when viewed 

 at margin (or through its greatest thickness) ; remaining thus long 

 dormant, and in that condition the "spindles" globular; pigment- 

 granules yellowish-green or bright red, rounded, or irregularly shaped, 

 very dense ; now and again putting on the energetic condition, and 

 forming a highly ramified, arborescent structure, the central mass then 

 presenting numerous rounded pulsating vacuoles; the "filamentary 

 tracks" extremely slender, quite hyaline, the "spindles" bluish in 

 colour', homogeneous in appearance, plastic, their progression slow,, 

 gradual, gliding ; when in motion, about toVo to iWo of an inch in 

 length, and about half as broad. 



