PALMELL1NA. 



[ 675 ] 



PALUDICELLA. 



containing green protoplasm, which by re- 

 peated binary division forms a swarm of 

 active 2-ciliated zoospores escaping by a 

 lateral or terminal slit (PL 5. fig. 2). 



Apiocystis. A simple attached sac with 

 a stout membrane, with green contents, | 

 consisting at first of groups of four still j 

 gonidia, which subdivide repeatedly, and as 

 the parent sac grows become converted into 

 innumerable active zoospores, which move 

 in the parent sac and then break out in a 

 swarm (PI. 5. fig. 5). 



Codiolum. An attached small, long cla- 

 vate sac, forming a stipes below, filled with 

 granular green contents, with starch-corpus- 

 cles, finally converted at once into nume- 

 rous globose gonidia, escaping by rupture of 

 the sac (PL 5. fig. 6). 



Hydrocytium . An attached minute shortly 

 stalked oblong sac, with green contents, ancl 

 a parietal starch-corpsule. Contents finally 

 divided into numerous 2-ciliated zoospores, 

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



Ophiocytium. Single or rarely in families ; 

 composed of a minute cylindrical curved 

 sac, with a short stipes, free 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). 



Sciadium. At first a stalked tubular sac, 

 with 8 gonidia, which grow from the orifice 

 in an umbel, finally emitting 2-ciliated zoo- 

 spores (PL 5. tig. 3). 



Chytridium. A minute parasitic globu- 

 lar or urceolate rooted sac ; cell-contents 

 colourless, finally converted into 2-ciliated 

 zoospores (PL 5. fig. 7). 



Pythium. Parasitic ; a colourless globu- 

 lar sac, living in the interior of diseased 

 Confervoids, often in groups, the neck per- 

 forating the nurse-plant, emitting active 

 gonidia (PL 5. fig. 8). 



BIBL. Braun, Rejuven., Ray Soc. 1851 ; 

 Alg. Unicell. 1855; Chytridium, 1856; 

 Nageli, JEinzell. Algen, 1849; Kiitz. Spec. 

 Alg. and Tab. Phycol. i. ; Cohn, Nova Acta, 

 xxiv. ; Rabenh. Alg. iii. ; Cooke, Fresh- 

 water Alga, 1882. 



PALMELLI'NA, Radlk. A doubtful 

 genus, allied to Palmella, or probably Fungi. 

 Thallus fl occulent; 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'RIA, Alder. A genus 

 of Escharidae (Cheilostomatous Polyzoa). 

 Orifice of the capsules with a palmate or 

 mucronate 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, Einzell. Alg. pi. 2. fig. B ; 

 Rabenh. Alg. iii. 43. 



PALMODIC'TYON, Ktz. A genus of 

 Palmellaceae (Confervoid Algae). 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 elliptical green cellules, 

 1-3000" in diameter, which ultimately es- 

 cape as active zoospores. This genus ap- 

 pears identical with Trypothcdlus, HOOK. 

 and Harvey, and is nearly related to HY- 

 DRTJRUS and TETRASPORA. 



P. rtifescens, Ktz., doubtfully referred 

 here, is larger ; it occurs near Aberdeen. 



BIBL. Kiitz. Sp. Alg. 234; Tab. Phyc. 

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



PALMOGIXEA, Ktz. See Cocco- 



CHLORIS. 



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

 Rabenh. Alg. iii. 116. 



PALMOPHYL'LUM, Ktz. A genus of 

 Palmellacese (Confervoid Algae). 1 species, 

 found in the Adriatic. 



BIBL. Rabenht. Flor. JEur. Alg. iii. 

 49. 



PALUDEL'LA, Ehr. A genus of Mee- 

 siaceae, having only one representative, 

 which occurs in Britain, P. squarrosa = 

 Bryum 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 



