726 



SYSTEMATIC HISTORY OF THE INFUSORIA. 



* Tlie subdivisions of the lobes spreading/ 

 in a ijlane at right angles to that of the 

 frond, (a, h, c.) 



MiCEASTERiAS muricata (Ralfs). — 

 Frond CLiiadrangiilar ; segments sub-5- 

 lobed, lobes opposite ; basal lobes tripar- 

 tite, middle lobes bipartite; end lobe 

 exserted and laterally divergent, its 

 lateral extensions bipaiiite ; all tlie sub- 

 divisions of all the lobes divergent and 

 disjjosed in a j^lfne at right angles to the 

 plane of the frond, their exti'emities ter- 

 minating in three or four projecting 

 points; the intervals between the lobes 

 deep rounded sinuations ; ends straight, 

 entlve. =JEifastrutn muricatum (Bailey). 

 U.S.A. 



2 * Tlie subdivisions of the lobes ^reading 

 in the same pla?ie as the frond. 



t Frond subelliptic ; segments 3- or sub- 

 5-lobed, lobes spreading, the intervals 

 between the lobes being wide ; lateral 

 lobe^ bipartite, their subdivisions di- 

 vergent, end lobe exserted and laterally 

 divergent. (a^6, c.) 



M. Baileyi (Ralfs). — Frond granulated 

 all over \ segments 3-lobed ; lateral lobes 

 deeply bipartite, subdivisions slender, 

 their exti-emities bidentate, the lower 

 subdivisions horizontal, approximate to 

 those of the opposite segment, the upper 

 divergent; end lobe naiTow below, ex- 

 serted, transversely expanded, its lateral 

 extremities truncate; ends concave, 

 U.S.A. 



M. ringens (Bailey). — Frond some- 

 what coarsely granulated at the 7nargin ; 

 segments 3-iobed ; lateral lobes some- 

 what broadly bipartite, stout, divergent 

 from those of the opposite seginent, 

 their subdivisions ha^-ing the extremities 

 obscm-ely bidentate; end lobe nan'ow 

 below, exserted, transversely expanded, 

 its lateral extremities obtuse ; ends con- 

 cave. U.S.A. 



M. furcata (Ag.). — Frond smooth ; 

 segments sub-5-lobed ; basal and middle 

 lobes bifid, their subdivisions slender, 

 linear, divergent, and forked at the apex, 

 bifm'cation usually incurved', end lobe 

 exserted, with a rounded sinus between 

 the considerably produced divergent ex- 

 tensions from the angles, which are ulti- 

 mately forked, their bifm*cations in- 

 curved. L. 1-135"; B. 1-156". = 31. 

 radiata (Hass.), 31. 3Ielitemis /3 gracilis 

 (Kg.). G.B., U.S.A. 



M. Crux-Melitcnsis (Ralfs). — Frond 

 smooth ; segments sub-5-lobed ; basal 



and middle lobes bifid, subdivisions 

 short, stout, and bidentate at the apex ; 

 end lobe exserted, with a roimded sinus 

 bet^'een the produced divergent exten- 

 sions from the angles, which are idti- 

 mately bidentate. L. 1-206" ; B. 1-221". 

 (i. 22). = Euastrum Cnix-llelitensis 

 (Ehr.) ; 31. 3Ielitensis (Menegh.). G. B., 

 F., a, Italy, U.S.A. 



2t Frond angular-elliptic, subquadi-ate 

 or suborbicular ; segments 3-lobed; 

 lobes spreading, the intervals between 

 the lobes being usually wide ; lateral 

 lobes either bipartite and inciso-den- 

 tate or tnmcate on outer margin ; 

 end lobe mostly exserted, divergent. 

 {a--b,c.) 



M. Americana (Ralfs). — Frond angu- 

 lar elliptic, more or less punctate ; seg- 

 ments 3-lobed; lateral lobes broad, 

 cuneate, their margins concave, inciso- 

 serrate; end lobe broad, cuneate, and 

 exserted, bipartite at the angles, the 

 subdivisions naiTOw, and minutely den- 

 tate at the extremities; end concave. 

 L. 1-204"; B. 1-254". (ii. 44, bad).= 

 Euastrum Americanum (Ehr.). G. B., 

 I., F., U.S.A. /3, margins waved rather 

 than dentate. 



M. foliacea (Bailey). — Frond sub- 

 quadrate, smooth ; segments 3-lobed ; 

 lateral lobes deeply bipartite, inciso- 

 dentate, their margins extending to an 

 equal distance from the middle line of 

 the frond, with a short rounded tootli- 

 like projection next the end lobe ; end lobe 

 narrow, somewhat dilated above, angles 

 emarginate ; ends concave. U.S.A. 



M. incisa (Kg.), — Frond about as 

 broad as long, suborbicular ; lateral lobes 

 horizontal, sides parallel, abruptly trun- 

 cate, tcith a tooth at each angle ; end lobe 

 short, very broadly cimeate, entire, its 

 angles acute. = Euastrum Crux-3Ielitensis 

 (Ehr,). G., F., U.S.A. ?^ 



M. decemdentatutn (Xag.). — Frond 

 about as broad as long, suborbicular; 

 segments 3-lobed; lateral lobes hori- 

 zontal, side subparallel, obscurely bipar- 

 tite, their subdivisions acutely bidentate; 

 end lobe broadly cuneate, entire, angles 

 acute; ends roimded. L. 1-55"'; B. 

 155"'. = 31. Neodamemis (Braun) ; 31. 

 Itzigsohnii (Breb.). F., G. 



3t Frond cu'cular; segments 5-lobed; 

 lobes approximate, the intervals be- 

 tween the lobes being linear or very 

 deep and acute incisions ; basal and 

 middle lobes dichotomouslv divided 



