330 W. ARCHER. 



Resume of Recent Contributions to our Knowledge 

 of " Freshwater Rhizopoda." Part IV. Compiled 

 by Wm. Archer, F.R.S. (With Plate XXI.) 



Rhizopoda Monothalamia Monostomata. 



Euglypha tincta, n. s., Archer.^ 

 The minute form which I have named above is well dis- 

 tinguished by its reddish colour ; every other Euglypha is 

 colourless. It is true it may be said to be " colourless" when 

 young (like Arcella vulgaris), but it is rare to meet with an 

 example absolutely so ; there is nearly always some amount 

 of tint, be it only of a slightly purplish character ; old exam- 

 ples are red or brownish, as highly coloured, in fact, as the 

 test of Arcella vulgaris. The test is minute, but somewhat 

 varying in size (as, indeed, do all the species), ovoid, com- 

 pressed, reddish, near the opening often somewhat paler; 

 hexagonal facets extremely minute, elongate ; test not pro- 

 duced into any elongate " neck," its opening bordered by in- 

 distinct " teeth," but usually indefinitely terminated, giving 

 an, as it were, torn aspect to the margin (as I said at the Club 

 meeting, as if '' unfinished" round the mouth j ; no spines; 

 the body-mass characteristically Euglyphan, nucleus (with 

 nucleolus) large, the usual zone of darkish granules across 

 the middle. The pseudopodia are seemingly more numerous 

 than in other Euglyphae, less fitful, that is, more slowly pro- 

 jected or altered in position or arrangement ; they seem to 

 form a tolerably steadily displayed tuft ; though, on the other 

 hand, one may often search long to find an example with 

 pseudopodia projected at all. One far more frequently meets 

 with abandoned tests than with those still in a living state. 

 The small size, the very minute facets, the ovate compressed 

 form of the test, with its irregularly bordered opening, and, 

 above all, the purplish, reddish, brick-red, or brownish 

 colour, very well distinguish this form, which I find not to 

 be very uncommon in certain situations. I have taken it 

 in the east and west of Ireland and in Scotland. 



Since the above was written I have for the first time seen 

 Professor Bailey's communications.^ I find it is extremely 

 probable that that observer has the priority, and that his 

 Ettglyphahrunneu may be truly identical with that described 

 above. 



I am very glad to find that Bailey has taken the correct 



' " Minutes of Dubl. Micr. Club " iu this Journal, vol. xvi, n. s., p. 107- 

 • 'I'roc. Acad, of Nat. Sci./ Philadelphia. 



