PALMODACTYLON. 



[ 489 ] 



PAPER. 



Gloeocystis, Nag. = Glaeocapsa. 



Porphyridium, Nag. = Palmella cruenta. 



Dictyosphcerium, Nag. = Palmella ? 



Stichococcus, Nag. = Protococcus. 



Nephrocytium, Nag. = decomposing spores 

 of Spirogyra ? 



Cystococcus, Nag. = Protococcus. 



Dactylococcus, Nag. = Protococcus. 



Ophiocytium, Nag. = ? 



Chlamidomonas, Ehr. = Protococcus. 



Chlamidococcus, Al. Br. = Protococcus. 



GlcBococcus, A. Br. = Coccochloris! 



Chytridium, A. Br,= probably a form ana- 

 logous to Characium, A. Br. (. sup.). 



PALMODACTYLON, Ktz. Perhaps 

 germinating spores of a Moss. 



PALMODICTYON, Ktz. A genus of 

 Palmellaceae (Confervoid Algae), described 

 as possessing a frond which appears like a 

 delicate network to the naked eye, of gelati- 

 nous texture, and consisting of anastomosing 

 branches, each composed (in P. viride) of a 

 single or double row of large vesicular cells, 

 1-600 to 1-960" in diam. These contain a 

 pair of elliptical green cellules, 1-3000" in 

 diameter, which ultimately escape as active 

 zoospores. This genus appears nearly re- 

 lated to HYDRURUS and TETRASPORA. 



P. rufescens, Ktz., doubtfully referred 

 here, is larger ; it occurs near Aberdeen. 



BIBL. Kiitzing, Sp. Ala. p. 234, Tab. 

 Phyc. Bd. i. pi. 31. 



PALMOGLGEA, Kiitz. (Cylindrocystis, 

 Menegh.). See COCCOCHLORIS. 



PALMOPHYLLUM, Ktz. Perhaps a 

 Prasiola. 



PALUDELLA, Ehr. A genus of Meesia- 

 cese, having only one representative, which 

 occurs in Britain, P. squarrosa =. Bryum 

 squarrosum, L. 



PALUDICELLA, Gervais. A genus of 

 Polypi, of the order Bryozoa, and family 

 Paludicellaida3. 



Char. Polypidom fixed, filamentous, dif- 

 fusely and irregularly branched, coriaceous, 

 consisting of a single row of club-shaped 

 cells arranged end to end ; apertures unila- 

 teral, tubular, placed near the broad end of 

 each cell; tentacular disk circular, with a 

 single row of free tentacles. 



P. articulata. The only species ; olive- 

 green ; polypes ascidian. Aquatic ; diameter 

 of filaments about 1-30 to 1-20". 



BIBL. Johnston, Brit. Zooph. p. 405; 

 Allman, Ann. Nat. Hist. xiii. 331, and Proc. 

 Irish Acad. 1843. 



PANDORINA, Bory. A genus of Vol- 

 vocineae (Confervoid Algae), the individuals 



of which consist of a globular hyaline vesicle 

 enclosing a mulberry-like assemblage of 

 green ciliated bodies, whose cilia project 

 through the enveloping membrane, and 

 effect a slow rotatory motion. The green 

 bodies resemble those of Volvox and Gonium, 

 and the solitary active forms of Protococcus. 

 Ehrenberg says they have but one cilium ; 

 this seems doubtful, and it is very possible 

 that these objects are forms of Volvox. 



P. Morum is 1-120" in diameter, its green 

 corpuscles 1-1150". (See VOLVOX.) 



BIBL. Ehrenberg, In/us, p. 53; Dujardin, 

 In/us, p. 317. 



PANOPHRYS, Duj. A term proposed 

 to designate certain Bursarice, E., in which 

 the row of larger cilia leading to the mouth, 

 characteristic of Bursaria, D., is absent. 



Dujardin's specific names are new, al- 

 though the species are old ! 



P.farcta, D. = Bursaria vernalis, B. leu- 

 cos, and B. flava of Ehrenberg. 



P. chrysalis (PI. 24. fig. 55). Marine. 



BIBL. Dujardin, In/us, p. 491. 



PANTOTRICHUM, Ehr. A genus of 

 Infusoria, of the family Cyclidina. 



Char. Body turgid, covered with vibratile 

 cilia. Aquatic. 



P. lagenula, E. (PL 24. fig. 58). Body 

 ovate, equally rounded at each end, yellow- 

 ish ; tegument produced anteriorly in the 

 form of a neck or truncate rostrum ; length 

 1-1080 to 1-580". 



P. volvox, E. Probably a young Para- 

 mecium (Dujardin). 



P. enchelys, E. = Enchelys nodulosa, D. 



BIBL. Ehrenberg, In/us, p. 247; Dujar- 

 din, Infus. p. 388. 



PAPER. Only a few general observations 

 can be made under this head. Ordinary 

 paper, as is well known, is generally manu- 

 factured from rags of linen or cotton fabrics, 

 so that it consists of a kind of felt of the 

 fibres of cotton or flax ; but other substances, 

 such as straw, for instance, are now coming 

 into use, from the growing scarcity of rags. 

 The manipulation to which the material is 

 subjected, together with the effect of fre- 

 quent washing in the case of rags, affects 

 the characters of the fibres to some extent, 

 and the cellulose is in some cases already 

 brought into that state in which iodine co- 

 lours it blue. The addition of sulphuric acid 

 and iodine always colours the fibres of paper 

 blue ; and care must be taken on this account 

 to avoid errors from the accidental presence 

 of them, when blotting-paper is used to ab- 

 sorb these reagents when applied to objects 



