336 NOTES ON FEESHWATEK ALG.E. 



cells are usually solitary, and generally have a well-defined integu- 

 ment surrounding them, which appears to arise by splitting off the 

 the cell-membrane. 



It comes nearest to 0. pusilla Hansg., from which it differs in 

 the obliquely elliptical cells with more pointed ends, its greater 

 relative breadth, and in the solitary cells being as a rule enclosed 

 in a well-marked integument. 



33. Tetraedron floridense, sp. n. T. mediocre, subirregu- 

 Iciriter octoedricum, marginibus leviter convexis, angulis bifidis, 

 divisione unaquaque producta, mamillata et subuucinato, cum spina 

 acuta subcurvata praedita ; membrana tenue et glabra. Diam. sine 

 spin. 34-44 /x, cum spin. 44-59 // ; long. spin. 3-8-5 fx. 



Hab. De Land, Florida, U.S.A. 



34. Tetraedron minimum (A. Br.) Hansg. 

 Hab. Urumi, Persia. 



StipitococcTis, gen. n. 

 Cellulae epiphyticse, gregarise, minute, stipite hyalino tenuissimo 

 longo affixae, base subrotundata, apice s^pe apiculato, nonnunquam 

 producto deinde irregulariter expanso, a vertice visffi circulares ; 

 contentus cellularum l»te viridis, chromatophora singula parietalia 

 curvata et irregulari, plasma granulosa. Propagatio ignota. 



35. S. urceolatus, sp. unica. Character idem ac generis. Lat. 

 cell. 3-4-2 //, altit. 6-5-10'5 /x; long. stip. hyal. 4-6 /x. 



Hab. Oughtershaw Tarn, W. Yorkshire (1800 ft.) ; epiphytic 

 on Mongeotia sp. 



This interesting alga occurred in large numbers closely clustered 

 round some filaments of Mougeoda ; it seems to be allied to the 

 genus Ferojiiella Gobi (Scripta Botan., Horti Univer. Imper. Petro- 

 politanae, tom. i. [1866-7J 244-250, t. i), which is an epiphyte on 

 filamentous DcsmidiacecB (e. g. P. hyalotheccB), but is, however, much 

 smaller and of a different form, the expanded and irregular apex 

 being remarkable. The stalk is extremely hyaUne, in fact barely 

 visible, and it is very likely, on account of its extreme tenacity, that 

 it was originally formed from the single cilium of a zoospore, as in 

 Peromelia, although it is comparatively much shorter. There was 

 no trace of a lateral crack for the escape of the zoospores, as in 

 Peromelia, and it is more probable that they would escape from the 

 expanded apex of the cells. The measurements of Peromelia in 

 DeToni's Sglloge Algarum appear to be wrong, according to Gobi's 

 figures (/. c). 



36. Kirchneriella obesa (West) Schmidle, var. pygm^a, var. n. 

 Var. minor, cellulis angustioribus et minus curvatis. Crass, cell. 2 fx. 



Hab. Keighley Moor, W. Yorkshire. This is a very marked 

 variety. 



37. Pleurococcus rufescens (Kiitz.) Breb. var. sanguineus, 

 var. n. Yar. in stratum mucosum densum molle, colore l?ete 

 sanguineus; contentum cellularum granulosum et laete sanguineum. 

 Diam. cell. 11-20 /x. 



