PALMELLINA. 



[ -'"'75 ] 



PALUJJICELLA. 



containing green protoplasm, wliicli by re- 

 peated biuar}' division forms a swarm of 

 active 2-ciliated zoospores escaping by a 

 lateral or terminal slit (PI. 5. tig. 2). 



Apiocystis. A simple attached sac with 

 a stout membrane, with green contents, 

 consisting at fii"st of groups of four still 

 gonidia, which subdivide repeatedly, and as 

 the parent sac grows become converted into 

 innumerable active zoospores, which mt)ve 

 in the paient sac and then break out in a 

 swarm (PL 5. tig. 6). 



Codioium. An attached small, long cla- 

 vate sac, forming a stipes below, tilled Avith 

 granular green contents, with starch-corpus- 

 cles, finally converted at once into nume- 

 rous globose gonidia, escaping by ruptm-e of 

 the sac (PI. 5. fig. 6). 



Hydrociftium. An attached minute shortly 

 stalked oblong sac, with green contents, and 

 a parietal starch-corpsule. Contents finally 

 divided into uiunerous 2-ciliated zoospores, 

 breaking out in a swarm (PL 5. fig. 1). 



Ophiocyfium. Single or rarely in families ; 

 composed of a minute cyhndrical cvirved 

 sac, v\-ith a short stipes, jfree or attached ; 

 green contents scattered, finally forming 8 

 gonidia in a row, set free by the circumscissile 

 rupture of the end of the sac (PL 5. fig. 11). 



Sciadiiim. A t first a stalked tubular sac, 

 with 8 gonidia, which grow fi-om the orifice 

 in an umbel, finally emitting 2-ciliated zoo- 

 spores (PL 5. fig. 3). 



C'hytridmm. A minute parasitic globu- 

 lar or urceolate rooted sac ; cell-contents 

 colom'less, finally converted into 2-ciKated 

 zoospores (PL 5. fig. 7). 



Pythium. Parasitic ; a coloiu'less globu- 

 lar sac, living m the interior of diseased 

 Confervoids, often in groups, the neck per- 

 forating the nm-se-plant, emitting active 

 gonidia (PL 5. fig. 8). 



BiBL. Braim, Hejuven., Hay Soc. 1861 ; 

 Alg. Unicell. 1855 ; Chytridium, 1856 ; 

 Nageli, Eiir^eU. Alyen, 18'49 ; Kiitz. Sj)ec. 

 Aly. and Tah. Phycol. i. ; Cohn, Noca Acta, 

 xxiv. ; Kabenh. Aly. iii. ; Cooke, Fresh- 

 icaicr Alyce, 1882. 



PAL.MELLI'NA, Radlk.— A doubtful 

 genus, allied to PahncUa, or probably Fmigi. 

 Thallus fl Occident ; cells very minute, some 

 smaller and globular, others larger, elliptical 

 or elongate. In the mud of wells and 

 fountains ; and beneath the epidermis of 

 the scalp ! 



BiBL. Rabenh. Aly. iii. 35. 



. PALME'RIA, Grev.— A genus of Dia- 

 tomacese from Hong Kong. 



BiBL. Grev. Ann. N. H. 1865, xvi. 1. 



PALMICELLA'IUA, Alder.— A genus 

 of Escharida3 (Cheilostomatous Polyzoa). 

 Orifice of the capsules with a palmate or 

 mucrouate process, with an avicularium on 

 its inner aspect. Four species ; marine, 

 deep water. (Hincks, Br. Zooph. 378.) 



PALMITIC ACID is a constituent of 

 most neutral animal and vegetable fats ; it 

 exists in combination with glycerine, form- 

 ing palmitine. When crystalline it forms 

 pearly scales. 



PALMODAC'TYLON, Nag.— A sup- 

 posed genus of Unicellular Algae, germina- 

 ting spores of a Moss ? 



P. varium consists of a group of radiating 

 single cells, or short multicellular filaments ; 

 ends rounded; numerous green masses in 

 each cell. The cell-wall bursting in definite 

 directions, sets free active gonidia. In 

 freshwater pools. 



BiBL. Nageli, EmzeJl. Aly. pi. 2. fig. B ; 

 Rabenh. Alq. iii. 43. 



PALMODIC'TYON, Ktz.— A genus of 

 Palmellacese (Confervoid Algse). Frond 

 forming a delicate gelatinous network, com- 

 posed of single or double rows of large vesi- 

 cular cells, 1-600 to 1-960" in diameter; 

 containing a pair of eUiptical gi-een cellules, 

 1-3000" in diameter, which ultimately es- 

 cape as active zoospores. This genus ap- 

 pears identical with Tryjwthallus, Hook, 

 and Harvey, and is nearly related to Hy- 

 DEURXJS and Tetbaspoea. 



P. rufescens, Ktz., doubtfully referred 

 here, is larger ; it occurs near Aberdeen. 



BiBL. Kiitz. -§j. Aly. 234; Tah. Phyc. 

 Bd. i. pi. 31 ; Rabenh. Aly. iii. 37. 



PALMOGLCEA, Ktz. See Cocco- 



CHXORIS. 



BiBL. Archer, Qu. Mic. Jn, 1864, 124; 

 Rabenh. Aly. iii. 116. 



PALMOPHYL'LUM, Ktz.— A genus of 

 Palmellacese (Confervoid Algae). 1 species, 

 found in the Adriatic. 



BiBL. Rabenht. Flor. Eur. Aly. iii. 

 49. 



PALUDEL'LA, Ehr.— A genus of Mee- 

 siaceae, having • only one representative, 

 which occurs in Britain, P. squarrosa = 

 Brxjum squarrosum, L. 



PALUDICEL'LA, Gervais.— A genus of 

 Polyzoa. 



Char. Polyzoary 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 



