HELICOSTEGIA. 



[ 384 ] HELMINTIIOSPORIUM. 



Helicosporium pid- 

 vinatuni. 



Magn. 200 diams. 



branched filaments ; but Fig. 313. 

 the distinctions are ob- 

 scui'e, as also those be- 

 tween Helicoma and Heh- 

 cusporium, the first of 

 which should have the 

 sjiirals closed, the latter 

 open. Fries and Berkeley 

 both include Helicotri- 

 chiim WM^^ixHelicosporium. 

 British species : 



H. puhinatum, Fr. (fig. 

 313 ). Forming a blackish 

 or olive pulvinate stratum 

 over v\Ood, with slender 

 branched filaments, bear- 

 ing yellowish-green strings 

 of sporidia coiled up into a spiral of about 

 three turns, very fugacious {Ilclicofrichuin 

 pulvinatum, JSees). 



If. vegetum, Fr. Widely pulvinate-eft'used, 

 subolivaceous, at length black; fertile fila- 

 ments erect, stifr, subrdate ; spores coiled 

 into a ring, .j-septate, greyish green. 



BiBL. Berk. Hook. Br. F/.'yvI ii. pt. 2. 

 335 ; A7m. N. H. 1850, vi. 434 ; vii. !)8 ; 

 Fries, Sj/d. Myc. iii. 353 ; Sum. Veg. 500 ; 

 Corda, Sturm, DeutscU. Flora., 3 ser. ii. pis. 

 15 & 10 ; Nees, Xova Acta, ix. 246, pi. 5. 

 15 ; Syst. Miicol. QS, fig. 09. 

 'HELICOSTE'GIA.— An order of Fora- 

 minifera, according to U'Orbigny's system, 

 comprising those coiled spirally on a single 

 axis. This feature, however, is common to 

 several genera which have distinct characters 

 of structure and habit, and has ceased to be 

 regarded as tvpical. 



IIELICOS'TOMA, Cohn.— A genus of 

 Holotrichous Infusoria = ^?/ss?</« with the 

 pharynx hooked at the end. II. oblonga ; in 

 salt water ; 1. 1-125". (Kent, Infiis. 501). 



HELlCOT'IlICnUM, Nees. See Heli- 

 cosporium. 



IlELIOPEL'TA, Ehr. 

 tomacese. 



Cltar. Frustules single (?) ; valves cir- 

 cular, with imperfect radiating septa, the 

 alternate intermediate portions of the valve 

 being depressed; markings absent in the 

 centre, but as many large submarginal 

 apertures (?) present as there are rays, and 

 numerous erect opposite submarginal spines 

 on each side. The spines coimect the pairs 

 of young frustules. 



//. metii. Frustules with six septa and 

 rays,threeof the intervals raised and coarsely 

 cellular, the alternate ones impri'sscd with 



%• 



A genus of Dia- 



fine 



decussating linos. 



the limb of the ra- 



diate margin broad ; marginal spines in the 

 middle of each cellular interval one or three, 

 in the others two or four ; umbilical star 

 slightly angidar; diameter 1-370". Ber- 

 muda. 



//. Leeuwenhoeckii, PI. 25. fig. 4. Three 

 other species, with a difierent number of 

 rays. 



The difierent appearances of the markings 

 upon the elevated and depressed portions of 

 the. valves evidently arise from the existence 

 of the ordinary depressions seen uatui'ally by 

 oblique and direct light. 



BiBL. Ehrenberg, Berl. Ber. 1844, 262 ; 

 Greville, 31ic. Tr. 1866, vi. 5 {new sp.). 



IIELMIN'THOSPO TIIUM, Link. — A 

 genus of Dematiei (Hyphomycetous Fungi), 

 growing on rotten wood &c., of which nu- 

 merous species are found in Britain. Tulasne 

 regards this genus as consisting of stylo- 

 sporous forms of Splueriacei. Currey refers 

 to this genus Corda's Dacfglium (Dendry- 

 phium) fianosum. The mycelium is often 

 somewhat gelatinous or indistinct ; on it 

 arise (often aggregated) erect, rigid, septate 

 filaments (Jjbres), on the summits of which 

 stand large, often club-shaped sejDtale spores. 

 liritish species : 



//. macrocarpum, Greville {Cn/pf. Fl. pi. 

 148. fig. 1). 



H. subulatum, Nees {Xova Acta. ix. pi. 5. 

 fig. 13). 



H. Clavariarmn, Desmazieres {Ann. Sc, 

 Nat. 2 ser. ii. pi. 2. fig. 2). 



H. vehitinum, Link (Grev. Crypt. Fl. 

 pi. 148. fig. 2). 



H. fusisporium, Berk. {Br. Flora, vol. ii. 

 part 2. 336). 



H namtm, Nees {Nora Acta, ix. pi. 5. 

 fig. 13 B; Syste7n. fig. 65). 



H. simjAex, Kunze (Nees, /. c. fig. 11). 



H. Tilice, Fr. (Berkeley, Ann. N. H. vi. 

 pi. 13. fig. 18). 



H. foUiculatum, Corda (7c. Funq. i. pi. 3 

 fig. 180). 



H. ohovatitm, Berk. {Ann. N. II. \\. pi. 13, 

 fig. 19) ; on old wet planks. 



//. delicatulum, Berk. (/. c. fig. 20) ; on 

 stems of Umbellifera3. 



//. Smithii, Berk, and Broome {Ann. N, II. 

 1851, vii. pi. 5. fig. 5). 



H. turhinatum, Berk, and Br. (I. c. fig. 6). 



II. Iiousselia7ium, Mojitagne {^Ann. Sc. 

 Nat. 3 ser. xii. 300). 



H. stktitiim, Berk, and Br. {Ann. N. II. 

 1854, xiii. pi. 15. fig. 10)! 



BiBL. Berkeley, Br. Fl. iii. pt. 2, 33(5 ; 

 Fries, Syst. iii. 354, and Sam. J'eyet. 5C0 



