HELICOSTEGIA. 



[ 384 ] HELMINTHOSPOmOI. 



Helicosporium pul- 

 vinatum. 



Magn. 200 diams. 



branched filaments; but Fig. 313. 

 the distinctions are ob- 

 scure, as also those be- 

 tween Helicoma and Heh- 

 cosporium, the first of 

 which should have the 

 spirals closed, the latter 

 open. Fries and Berkeley 

 both include Helicotri- 

 cJmm under Ifelicosporium. 

 British species : 



H. pulvinatum, Fr. (fig. 

 313). Forming a blackish 

 or olive pulvinate stratum 

 over wood, with slender 

 branched filaments, bear- 

 ing yellowish-green strings 

 of'sporidia coiled up into a spiral of about 

 three turns, very fugacious (Helicotrichum 

 pulvinatum, Nees). 



H. vegetum, Fr. Widely pulvinate-effused, 

 subolivaceous, at length * black ; fertile fila- 

 ments erect, stiff, subulate ; spores coiled 

 into a ring, 3-septate, greyish green. 



BIBL. Berk. Hook. Br. FL vol. ii. pt. 2. 

 335 ; Ann. N. H. 1850, vi. 434 ; vii. 98 ; 

 Fries, Syst. Myc. iii. 353 ; Sum. Veg. 500 ; 

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

 15 & 16 ; Nees, Nova Acta, ix. 246, pi. 5. 

 fig. 15 ; Syst. Mycol 68, fig. 69. 



HELICOSTE'GIA. An order of Fora- 

 minifera, according to D'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 typical. 



JHELICOS'TOMA, Cohn. A genus of 

 Holotrichous Infusoria = Nassula with the 

 pharynx hooked at the end. H. oblonga ; in 

 salt water ; 1. 1-125". (Kent, In/us. 501). 



HELICOT'RICHUM, Nees. 'See HELI- 



COSPORIUM. 



HELIOPEL'TA, Ehr. A genus of Dia- 

 tomacese. 



Char. 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 connect the pairs 

 of young frustules. 



H. metii. Frustules with six septa and 

 rays, three of the intervals raised and coarsely 

 cellular, the alternate ones impressed with 

 fine decussating lines, 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 angular; diameter 1-370". Ber- 

 muda. 



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

 other species, with a different number of 



The different appearances of the markings 

 upon the elevated and depressed portions of 

 the valves evidently arise from the existence 

 of the ordinary depressions seen naturally by 

 oblique and direct light. 



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

 Greville, Mic. Tr. 1866, vi. 5 (new so.). 



HELMIN'THOSPO'RIUM, 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 Sphaeriacei. Currey refers 

 to this genus Corda's Dactylium (DENDRY- 

 PHIUM) fumosum. The mycelium is often 

 somewhat gelatinous or indistinct ; on it 

 arise (often aggregated) erect, rigid, septate 

 filaments (fibres), on the summits of which 

 stand large, often club-shaped septate spores. 

 British species : 



H. macrocarpum, Greville (Crypt. Fl. pi. 

 148. fig. 1). 



H. subulatum. Nees (Nova Acta. ix. pi, 5. 

 fig. 13). 



H. Clavariarum, Desmazieres (Ann. Sc, 

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



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

 pi. 148. fig. 2). 



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

 part 2. 336). 



H nanum, Nees (Nova Acta, ix. pi. 5. 

 fig. 13 B ; System, fig. 65). 



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



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

 pi. 13. fig. 18). 



H. folliculatum. Corda (Ic. Fung. i. pi. 3 

 fig. 180). 



H. obovatum, Berk. (Ann. N. H. vi. pi. 13. 

 fig. 19) ; on old wet planks. 



H. delicatulum, Berk. (I. c. fig. 20) ; on 

 stems of Uinbelliferae. 



If. Smithii, Berk, and Broome (Ann. N. If. 

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



If. turbinatum, Berk, and Br. (1. c. fig. 6). 



H. Rousselianum, Montague (Ann. /Sc. 

 Nat. 3 Sr, , xii. 300). 



H. stictitum, Berk, and Br. (Ann. N. If. 

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



BIBL. Berkeley, Br. Fl. iii. pt. 2, 336 ; 

 Fries, Syst. iii. 354, and Sum. Veyet. 500 



