TYPHLINA. 



[ 790 ] 



ULVACE^. 



■when mature escape from the pore in a 

 tencbil (as in Ci/tisjwra) if moistened or 

 pressed (see also Cenangium). 



BiBL. Berk. £r. Fl. ii. pt. 2. 210 ; Ann. 

 N. H. 2. vii. 185 ; Hook. Jn. Bof. iii. 322 ; 

 Tulasne, Ann. Sc. Nat. 3. xx. 143, pi. 16. 

 figs. 15, 16 ; Fries, Sutn. Veg. 399 ; Gre- 

 yille, Crypt. Fl. pi. 335. 



TYPH'LINA, Ehr.— An imperfectly ex- 

 amined genus of Eotatoria, of the family 

 PhUodinaja. T. viridis (Pi. 44. fig-. 33). 

 Found in Egypt. (Ehrenberg, Inf. 483.) 



TYROG'LYPHUS. See Acarus. 



TYUO'SINE. — This substance is gene- 

 rally found associated with leucine. It 

 forms silky-white needles, often in stellate 

 groups, difficultly soluble in water, and en- 

 tirely insoluble in alcohol and ether. When 

 warmed with sulphuric acid, and perchloride 

 of iron is added, it is rendered violet. The 

 little white grains found upon anatomical 

 preparations preserved in spirit consist of 

 tyrosine. (Hoppe-Seyler, Anah/se Chim, ; 

 ¥vej,mst.51.) 



U. 



U'LOTHRIX. — A genus of Confervacese 

 (Couferyoid Algse), allied to Draparnaklin 

 and Stiyeoclonium. They consist of un- 

 branched filaments, adhering loosely toge- 

 ther to form a mucous stratum, growing 

 upon stones &c. in fresh water. The fila- 

 ments are composed of short hyaline cells 

 (PI. 9. fig. 6), the green contents of which 

 are at first granular, adhering to the waUs 

 (a), then contracted into transverse bands 

 (h). Contractile vesicles have been ob- 

 served in the cells of some species. Ac- 

 cording to recent observations, macrospores 

 with four cilia occur singly or in twos, 

 in certain cells ; while in others, numerous 

 biciliated microspores are formed, which 

 conjugate and produce resting spores ; these 

 again give rise to zoospores, from which 

 new filaments arise. 



U. zoyiuta. Filaments 1-9G0" in diame- 

 ter, joints about as long {Lynghya zon., 

 Hass. pi. 59. figs. 2, 3, & 6). 



U.^jectmalis. Filaments 1-1800" to 1-9G0" 

 in diameter, joints half or a fourth the 

 length; fertile cells swollen (Hass. pi. 00. 

 figs. 1-5). 



U. crispa. Filaments very long, 1-600" in 

 diameter, joints half or a third as long {Con- 

 ferva hico'hr, Enq. Hot. p. 2288). 



_ U.floccosa. Fiiaments 1-2100" to 1800" in 

 diameter, joints about as long {Lynghya 

 floccosa, Hass. pi. 60. figs. 1 & 2). 



U.puncialis. Filaments 1-3000" to 1-2500" 

 in diameter, regularly torulose ; joints two 

 and a half times as long as broad {Lyngb. 

 jnmct., Hass. pi. 00. fig. 4 ; including per- 

 haps L. virescens and L. vermicularis) . 



U. spedosa. Filaments 1-780" to 1-420" 

 in diameter, curled ; sterile joints half or a 

 third as long. 



U. mucosa, Thuret (PI. 9. fig. 6). Pale 

 green or yellowish, slimy ; joints usually as 

 long as broad, sometimes shorter, 1-3000" in 

 diameter. 



BiBL. Kiitzing, *S^. Alg. 345 ; Tab. Phyc. 

 ii. ; Hassall, Ah/. 219; Thuret, Ann. Sc. N. 

 3. xiv. 222, pi. 18 ; Rabenht. Alg. iii. 365 ; 

 Cramer, Bof. Zeit. 1871 ; Dodel, PringsheinCs 

 Jahrb. x. 417. 



UL'VA, Linn. — A genus of Ulvacese 

 (Confervoid Algae), here taken in the sense 

 of Thuret. The plants are all marine, con- 

 sisting of broad, green, simple, or lobed, 

 membranous fronds, growing upon rocks 

 and stones. The cells are rounded-angular 

 (PI. 9. figs. 2 & 3), and are at fii-st filled 

 with amorphous green colouring-matter, 

 which subsequently becomes collected into 

 masses (a), ultimately converted into nu- 

 merous zoospores. Under the influence of 

 light, those soon " swarm " and break out 

 from the cells by a pore in the outer wall 

 (fig. 3 6). The emptied cells give a pale 

 colour to the parts of the frond where they 

 are situated. The zoospores appear in two 

 forms, some large and bearing four cilia 

 (fig. 3 c), others much smaller and pos- 

 sessed of only two cilia (fig. 2 b). The 

 fronds in which the latter occur are gene- 

 rally of a yellower colour. Thuret has seen 

 botii kinds germinate. As defined by that 

 author, the British species stand as fol- 

 lows : — 



U. Lactuca, L. Frond broadly ovate or 

 oblong, 6 to 18" long, and several inches 

 wide. 



i3. kdissima. Frond 3' or more long, 18" 

 or more wide ; found in the muddy water 

 at the entrance of harbours {PJiycoseris My- 

 riotrema, Kiitz. Sp. Alg.)= U. orbiculata. 



U. Linza, L. Frond linear-lanceolate, 

 6 to 24" long, i to 1^" wide. 



BiBL. Harvey, Mar. Alg. 216, pi. 25 B; 

 Thuret, Mem. Sue. Cherbourg, ii. ; Ann. Sc. 

 Nat. 3. xiv. 224, pi. 20 ; Greville, Harvey, 

 Kiitzing, Algce ; Kabenht. Fl. Eur. Alg. i. 

 316. 



ULVA'CE/E.— A family of Confervoid 

 Algaj. Marino or freshwater Alga?, con- 

 sisting of membranous, expanded, saccate 



