117 



it, conceiving it to be some foreign filament; but a further 

 examination of the specimens at command soon revealed the 

 novel fact that we had indeed to do with a truly stijntate [all 

 but Radiolarian) Rhizopod, and this error or oversight I was 

 able to correct at the subsequent meeting. 



The genus in question may be, I think, characterised as 

 follows : 



Genus, Clathrulina (Cienk.). 



An " Actinophryan" Rhizopod, without a '' central cap- 

 sule," and enclosed within a hollow," globular, fenestrate 

 siliceous " shell" (or " skeleton"), the pseudopodia radiating 

 all around through its apertures, and which is borne aloft at 

 the summit of a slender stipes, the latter attached by a some- 

 what expanded base to foreign objects, or one to another. 



Clathrulina elegans (Cienk.). 



Specific characters. — Body colourless, granular, vacuolar, 

 very mobile, in a young state showing a pale central " nu- 

 clear" structure ; the perforate " shell" when young pale and 

 colourless, Avhen older more or less brownish ; the apertures 

 roundish or subpolygonal, bounded by a kind of raised rim, 

 thus producing a groove or furrow, varying in width, between 

 them ; the stipes in length two to six times the diameter of 

 the " shell,"*^ colourless ; the pseudopodia nimierous, fine, 

 often long, colourless, granuliferous, slightly branching. 



Reproduction of two kinds — (1) by self-fission into two, 

 and eventual passage forth through the apertures of the shell 

 of the individualised sarcode bodies, which presently assume 

 the inherent Actinophryan characteristics, reproducing the 

 Clathrulina by development of stipes and shell; (2) by 

 formation of motile (ciliated ?) embiyos, originating from a 

 separately encysted condition within the " shell" of the sar- 

 code body, mostly previously subdivided into several portions, 

 each enclosed by a firm coat. These, after a period of rest 

 (often long), permit the escape each of a motile monad-like 

 embryo, showing a nucleus and nucleolus, which after a 

 brief period passes out through an aperture of the shell and 

 settles near at hand (not unfrequently upon the just quitted 

 primary Clathrulina), and (like the individualised portion of 

 a Clathrulina subdivided without passing into an encysted 

 and embryo state) at once ptits forth pseudopodia, develops 

 a stipes and shell, and thus prodtices a new Clathrulina. 



Cienkowski refers to Avhat he calls a variety of C. elegans 

 (designated as minor), which he considers marked by its 



VOL. X. NEW SER. I 



