722 



SYSTEMATIC niSTORY OF THE INFUSORIA. 



numerous minute scattered granules 

 endochrome sometimes bitid at the ex 

 tremities, usually with a pale space at 

 the centre, and with a longitudinal me- 

 dian series of lighter-coloured dense cor- 

 puscles. Sporangium same as precedino- 

 species. (iii.l,2.) L. 1-100" ; B.l-2:350'\ 

 JJocidium aHperum (Ralfs) ; Leptocijsti- 

 nema aspenon (Archer). G.B., I., F., G. 



G. Brehissonii (De B.). — Joints nar- \ varjdng in length. 



; I row-fmiform, subcapitate at ends, loosely 

 j united, often single, rough on the surface 

 j with minute scattered gi*anules ; endo- 

 chrome usually with a pale space at the 

 . centre, and a median series of corpuscles. 

 Sporangium as preceding. Dociduim 

 ' asperum (Breb.) ; Lep. Fort it (Archer). 

 L. 1-200" to 1-105"; B. 1-3500". L, 

 F., G. /3 much smaller, and joints 



Genus LEPTOCYSTIXEMA (Archer).— Filament attached, cyHndrical ; 

 joints elongate, cylindrical, slender, linear, without a constriction or inflation, 

 ends truncate ; endochrome a longitudinal Jlattened hand. (No e\ident gela- 

 tinous sheath.) 



A genus under the above name was founded by Mr. W. Archer (Nat. Hist. 

 Rev. vol. V. p. 250) for the reception of the single species now here included, 

 as well as the two species of Gonatozygon (De B.), not being, however, then 

 aware that De Bary had pre\iously established the latter genus in ' Hedwigia.' 

 However, as the reproductive condition of Lep. Kinahani (Archer) is yet 

 unlmown, we deem it more acMsable to allow that species to remain under 

 its original name, and, for the present at least, to retain the genus, distin- 

 guishing it here from Gonatozygon by the filaments being attached (a singular 

 circumstance in Desmidiacese), and the endochrome a flattened band. The 

 species is very distinct indeed from the two preceding. 



Leptocystestema Kinahani (Archer). 

 — Filament 2 to 3 inches long, often 

 breaking up into separate joints; joints 

 20 to 40 times as long as broad, linear, 

 smooth ; endochrome in its broader dia- 

 meter filling the entire width of the 

 joint — in the narrower, not more than 

 -one-third, occup}dng the centre of the 

 joint, and at the central pale space 



curved towards the ceU-wall, and hav- 

 ing imbedded within it a longitudinal 

 median series of globular, light-coloured, 

 dense corpuscles (one occuppng the 

 centre of the pale space), retracted at 

 each end of the joint, leaving a clear 

 space in which are active granules. 

 Sporangium unknown. L. 1-200" to 

 1-50"; B. 1-1900". (m. 4.) I. 



2. Joints mostly broader than long, very seldom slightly longer than broad. 



Genus HYALOTHECA (Ehr.). — Filament ci/Iindrical, very gelatinous; 

 joints having either a slight constriction, which produces a crenate appearance, 

 or a grooved rim at one or both ends, Avhich forms a bifid projection at each 

 side ; end view circular ; endochrome radiate. 



Hyalotheca dissiliens (Br(5b.). — Fila- 

 ment fragile, crenate ; joints usually 

 broader than long, with a shallow groove 

 round each, dividing the endochrome 

 into two portions. Sporangium globular, 

 smooth, placed within the persistent 

 connecting tube formed by the mutual 

 fusion of a fresh extension from, and 

 produced between, the sides opposed to 

 each other of the conjugating pairs of 

 joints, the filament having previously 

 broken up into single joints, (ii. 32 & 35). 

 L. 1-2105" to 1-1351"; B. 1-1308" to 

 1-833". = Conferva dissiliens (Smith), 

 Glaoprium dissiliens (Berk., Hass.), Hya- 

 lotheca mucosa (Kg.). G.B., I., F., G., 

 U.S.A. 



H. mucosa (Ehr.). — Filament scarcely 

 fragile, mucous sheath very broad; joints 

 about as broad as long, not constricted, 

 hut having at one of the ends a mimite 

 hidentate projection on each margin, the 

 adjoining end of the next joint being 

 similar, these projections being produced 

 bv an annular grooved rim. L. 1-1250" 

 to 1-6G0'; B. 1-1250" to 1-1111". 

 = Conferva w«/cos«(Mert.,Hook.,Harv.), 

 Gloeoprium mucoswn (Hass.), H. Ralfsii 

 (Kg.). G.B.,I.,F. 



H. ? duhia (Kg.). — Filament without a 

 mucous sheath (?) ; joints rather broader 

 than long, with two puncta near each 

 margin. G. 



