HOW TO KNOW THE FRESH-WATER ALGAE 



Hormidiopsis 1 05 

 ellipsoideum 1 05 



Hormidium 107; also 104- 

 106 

 Klebsii 107 



Hormotila 99 

 mucigena 99 



Hot Springs 1 3 



H-SHAPED SECTIONS: seg- 

 ments of filaments or ter- 

 minal cells of filaments 

 which result from separa- 

 tion of cells, one from 

 the other, at the midre- 

 gion rather than at the 

 cross walls, the cell wall 

 being composed of two 

 sections which adjoin and 

 overlap midway between 

 the end walls. (See Figs. 

 172, 212); also in a chlo- 

 roplast shape where there 

 are 2 broad sections ly- 

 ing along the side walls 

 and connected by a nar- 

 row cross band. Fig. 351 



Figure 351 



Hyalobryon 1 46 



mucicola 1 46 

 Hyalotheca 90; also 88, 135 



dissiliens 90 



mucosa 90 

 Hydra 65 

 Hydrocoleum 1 64 



homeotrichum 1 64 



oligotrichum 1 64 

 Hydrodictyon 54 



reticulatum 54 

 Hydrurus 1 44 



foetidus 1 44 

 Hye//a 176 



iontana 1 76 



INCISED; MEDIAN INCI- 

 SION: cut in; with a 

 narrow cut from the mar- 

 gin. Fig. 352 



i/ 



' 



Figure 352 



Indian Turnip 66 



INFOLDED: as in cross walls 

 of a filamentous alga 

 which are not smooth, 

 even membranes but have 

 folds extending back into 

 the cavity of the cell. 

 Desmidium and certain 



species of Spirogyra have 

 this type of wall; repli- 

 cate. 



INTERCALARY: arranged in 

 the same series, as spores 

 or heterocysts which oc- 

 cur in series with vegeta- 

 tive cells rather than be- 

 ing terminal or lateral. 



INTERNODE: the space or 

 section of a filament or 

 rhallus extending between 

 branch - bearing or en- 

 larged portions (nodes). 



INTERSTICES: openings or 

 spaces between adjoined 

 cells; openings in the 

 mucilage which incloses 

 colonial algae. 



INTESTINIFORM: a thallus 

 in the form of a tube, 

 often crinkled, sometimes 

 branched. 



INVAGINATION: concavity; 

 a depression from an oth- 

 erwise smooth or plane 

 surface. 



IODINE TEST: application of 

 a weak solution of iodine 

 (Lugol's) to determine 

 presence of starch; starch- 

 iodide, which is formed 

 when iodine is applied to 

 cells of the Chlorophyta, 

 appears as a blue-black 

 substance. 



ISODIAMETRICAL: a figure 

 with all planes having an 

 equal diameter or nearly 

 so. 



ISOGAMETE: a sex cell 

 which shows no detect- 

 able differentiation in re- 

 spect to maleness or fe- 

 maleness. 



JOINT: point or plane where 

 two cells or elements ad- 

 join. 



Jack-in-the-pulpit, see Ari- 

 saema 



K 



KELP: common name for 



the larger brown sea 



weeds. 

 Kentrosphaera 84 



Bristolae 84 

 Kirchneriella 49, 65; also 53 



lunaris 49 



obesa var. major 49 



Lagerheimia 79, 84; also 56 



longiseta 79 



quadriseta 79 

 Lagynion 147 



reductum 147 



triangularis var. pyramida- 

 tum 147 

 LAMELLA; LAMELLATE: 



with layers; with plates 



lying against one another. 



LAMINARIN: a polysaccha- 

 ride carbohydrate used as 

 food storage in Phaeo- 

 phyta. 



LAMINATE: plate-like; lay- 

 ered. 



LATERAL CONJUGATION: 

 reproduction involving the 

 formation of a connect- 

 ing tube around the end 

 wall of two adjacent cells 

 in the same filament so 

 that contents of the cell 

 may fuse to form a zygo- 

 spore. 



Lemanea 124 

 annulata 124 



Lemna 12, 37, 66 

 trisulca 12, 66 



Lepocinclis 25 

 acuta 25 

 glabra fa. minor 25 



Leptosira 117; also 22 

 Mediciana 1 1 7 



LEUCOSIN: a whitish food 

 reserve characteristic of 

 many of the Chrysophyta, 

 especially the Heterokon- 

 tae; gives a metallic lus- 

 tre to cell contents. 



Leuvenia 137 

 natans 1 37 



LICHEN: a duplex plant 

 thallus formed by a fun- 

 gus and an alga living in 

 close association, 80, 109. 



Lime (Marl Deposits) 21 



LINEAR SERIES: cells or 

 units arranged in a single 

 row. 



Lobomonas 33 

 rostrata 33 



LOBULE: a small lobe; a 

 secondary division of a 

 lobe. 



LONGITUDINAL FURROW: a 

 groove in the dinoflagel- 

 late cell which extends 

 parallel with the long 

 axis. 



LORICA: a shell-like struc- 

 ture of varying shapes 

 which houses an organism, 

 has an opening through 

 which organs of locomo- 

 tion are extended. (See 

 Trachelomonas, Fig. 5.) 

 Fig. 353 



Figure 353 



LUNATE: crescent - shaped, 

 as of the new moon. 



Lyngbya 159, 162 

 Birgei 1 59 

 contorta 1 59 



204 



