HYPNUM. 



[ 408 ] 



HYPOGiEI. 



double, single, or absent, the internal or the 

 external or both being occasionally obsolete. 

 External : sixteen equidistant or more or 

 less geminate teeth, lanceolate, trabeculate, 

 "with a longitudinal line, composed of a 

 double layer, arising below the orifice, 

 sometimes split into several irregular arms. 

 Internal : similar to the above, or capillary, 

 placed on a more or less exserted mem- 

 brane, conjoined by transverse appendages, 

 very often wholly or partly caucellate. No 

 interposed cilia. 



PilotrivJium. Calyptra mitriform. Pe- 

 ristome, &c. as in Neckeea. 



b. Internal peristo7ne ivith inteiyosed cilia. 



Hookeria. Calyptra mitriform. Peri- 

 stome double ; external teeth lanceolate- 

 subulate, with a more or less broad longi- 

 tudinal median line, trabeculate ; internal 

 on a more or less deep keeled membrane, 

 subulate, scarcely ciliiform ; rudimentary 

 cilia interposed, hardly conspicuous, or, 

 more rarely, perfect. 



Ilypnum. Calyptra dimidiate. Peri- 

 stome double. External teeth sixteen, lan- 

 ceolate, trabeculate, with a more or less 

 broad longitudinal line, more rarely a fis- 

 sure, with more or less crest-like prominent 

 trabeculfe within. Internal teeth on a 

 grooved reticulated projecting membrane, 

 lanceolate, articulated, grooved, solid or 

 perforated in the middle, or altogether 

 gaping and separating. Cilia one to four, 

 interposed, very often rudimentary. 



IIYP'NUM, Dill.— A large genus of 

 Hypnoide?e (Pleurocarpous Mosses), here 

 including the species referred b}' modern 

 writers to Isothecium, Climacimn, Let:kea, 

 &c. Many of them are extremely common 

 in all woods, growing on trunks of trees, 

 banks, kc. ; others gTOw in water or in bogs, 

 &c. The distinctions of the species are 

 taken in gi-eat part from the forms &c. of 

 the leaves, which require the use of a 

 microscope for their accurate determination. 



BiBL. AVilson, Ih-ijol. Br. 3.35 ; Hooker, 

 Br. Flora, vol. ii. pt. 1 ; Miiller, Syn. Mus- 

 corum. 



IIYPO'CREA, Fr.— A genus of Sphfe- 

 riacei (Ascomycetous Fungi), with a hori- 

 zontal, sessile, or indistinct ileshy, mostly 

 coloured stroma, filiform asci, and simple 

 spores. The species of this genus, like 

 those of Tljipoxj/lon, as given by Fries, are 

 partly r(>ferred to Sphceria by other authors ; 

 the distinctions will be best explained by 

 taking' all these genera under Sph.^bia. 



HYPO'DERAS, Frauenfeld.— A genus 

 of Acarea (Acarina). Numerous species, 

 occurring beneath the skin of birds, often 

 forming little cysts. — Giebel, Verh. zool.- 

 bot. Gescll. Wien, xiv. 385; Miu-ray, He. 

 Ent. 228 (figs.); Robertson, Jn. Mic. Soc. 

 vi. 201. 



HYPODER'RIS, R. Brown.— A genus 



Ficr. 351. 



Hypoderris Browuii. 



Borus with fringed indusium. 



Magniiied 25 diameters. 



of Dicksonieae (Polypodiaceous Ferasj, 

 with very prettily fringed indusia. Exotic. 

 (Hooker, »S'y«. 4().) 

 HYPOG^'L— A family of Gasteromy- 



Fig. 352. 



Hydnangium eandidiim. 



Basidiospore8 upon the hymenium. 



Magnified 400 diameters. 



Fig. 353. 



Hysterangium clatliroides. 



Section of hymeniura with oval bnsidiospores. 



Magnified 400 diameters. 



cetous Fungi, characterized by their resem- 

 blance to the Truffles (Ascomycetes) in 



