470 



Si:STEMATIC HISTOKY OF THE INFUSORIA. 



rather larger than the others ; e.y. with 

 three somewhat rounded angles, sides 

 convex, and bordered all round ivith the 

 spines. L. 1-506" to 1-418" ; B. 1-523" 

 to 1-476". (hi. 22, e. v. 23.) = Des7nidmm 

 ramostnn (Ehr.), Asteroxanthium ranio- 

 smn (Kg.), Phycastrum Griffithsianum 

 (Nag.). G.B., i., F., G., U.S.A. 



S. scabrum (Breb.). — Segments in f.v. 

 siibelUptic or broadly fusiform, very 

 rough or denticulate at the margin ; e.v. 

 with three rounded denticulate angles, 

 sides straight, bordered by minute, short, 

 truncate emarginate sjjines. F. 



S. asperum (Breb.). — Segments in f.v. 

 broadly elliptic, very rough, with very 

 viinute, short, truncate or forked spines 

 chiefly confined to the outer margin; 

 e.v. with three rounded angles, sides 

 straight. Sporangium orbicular, beset 

 with numerous elongate spines, twice 

 branched at the apex. L. 1-555"; B. 

 1-615". G.B., I., F. 



Segments without spines , 

 rounded. 



t Frond smooth. 



?.r. angles 



S. muticum (Breb.). — Segments in f.v. 

 elliptic, smooth, without spines ; e.v. with 

 three or four broadly rounded angles, sides 

 concave. Sporangium beset with nume- 

 rous elongate somewhat stout spines, 

 forked at the apex. L. 1-674": B. 

 1-686". = S. trilobum (Menegh.), Phyc- 

 astrum muticum (Kg.), P. depressum 

 (Niig.). G.B., I., F., Italy, U.S.A. 



S. orbicidare (Balfs). — Segments in 

 f V. semiorbicidar, smooth, without 

 spines ; e. v. with three broadly rounded 

 angles, sides slightly concave. L. 

 1-1037"; B. 1-110)6" . = Desmidium orbi- 

 cular e (Ehr.), Phycastrum oi'hiculare 

 (Kg.), Goniocystis ( Trigonocystis) orbi- 

 cularis (Hass.). G.B., I., F., G., Italv, 

 U.S.A. 



S. coarctatum (Breb.). — Segments ob- 

 long, lateral extremities rounded, inner 

 margin convex, outer somewhat concave at 

 the centre (inversely reniform), smooth ; 

 e.v. with three injlated rounded angles, 

 sides concave. F. 



^.pygmceum (Breb.). — Segments in f.v. 

 cuneiform, outer margin slightly convex, 

 smooth ; e.v. with three blunt angles, 

 sides slightly convex. Sporangium orbi- 

 cular, " beset with protuberances bearing 

 each two bifurcate spines at their sum- 

 mits." F., G. 



2t Segments having the projecting por- 

 tions surrounded by annular transverse 



lines (rows of puncta or minute gra- 

 nules ?). 



S. striolatum (Nag. sp.). — Segments 

 in f. V. reniform, divergent, ends concave, 

 each of the lateral portions crossed by 

 about Jive transverse lines (annular rows 

 of closely set puncta or minute gra- 

 nides?); e.v. with three rounded angles, 

 sides concave, each of the projections 

 crossed as before by about five transverse 

 lines, the central portion smooth. L. 

 1-100". = Phycastrum striolatum (Nag.). 



3t Fronds rough superficially with scat- 

 tered granules. (Sometimes S. tri- 

 corne might be thought almost to come 

 in here ; but the extremities in that 

 species are more prolonged into di- 

 stinct processes, usually colourless, 

 and mostly divided at the apex. Here, 

 also, might S. asperum and S. scabrum 

 seem to fall in ; but they are provided 

 with very short and trimcate spines on 

 some part of their margin.) 



S. muricatum (Breb.). — Segments suh- 

 elliptic, the outer margin more turgid 

 than the inner, rough all over with 

 scattered conic granules', e.v. with three 

 angles, both angles and sides broadly 

 rounded. L. 1-409"; B. 1-47^". = Des- 

 midium apiculosuni (Ehr.), Xanthidium 

 deltoideuni (Corda), Phycastrum ajnculo- 

 sum (Kg.), P. muricatum (Kg.)? Gonio- 

 cystis (Trigonocystis) muricata, /3 (Hass.). 

 G.B., F., G., Italy. 



S. punctidatum (Breb.). — Segments in 

 f.v. elliptic, equal, rough with scattered 

 j}uncfa-like granules; e.v. with three 

 broadlv rounded angles, sides concave. 

 L. 1-704" ; B. 1-881". G B., I., F. 



S. rugulosum (Breb.). — Segments in 

 f.v. broadly elliptic, equal, rough with 

 scattered granules, giving a denticulate 

 appearance to the margin, especially at 

 the opposite lateral extremities ; e.v. with 

 three broadly rounded denticulate angles, 

 sides straight or nearly so. F. 



S. pileolatum (Breb.). — Segments in 

 f.v. quadrate, the basal angles rounded 

 and rough with mimde granules, sides 

 with a broad shallow sinus, the upper 

 margin terminating in three conspicuous, 

 large, rounded, conical, very slightly di- 

 vergent projectiotis, which are rough with 

 minute granules ; e.v. with three rounded 

 angles, sides entire. F. 



S. Capitulum (Breb.). — Segments in 

 f.v. quadrate, sides with a rounded sinus 

 at the middle, the basal and upper angles 

 crenated, rounded, upper margin straight ; 



