HYPODERRIS. 



[ 337 ] 



HYPOPUS. 



(Ascomycetous Fungi), with a horizontal, 

 sessile, or indistinct stroma, filiform asci and 

 simple spores. The species of this genus, 

 like those of Hypoxylon, as given by Fries, 

 are partly referred to Sphceria by other au- 

 thors ; the distinctions will be best explained 

 by taking all these genera under SPH^ERIA. 

 HYPODERRIS, R. Brown. A genus of 

 Cyathaeous Ferns, with very prettily fringed 

 indusia. Exotic. 



Fig. 355. 



Hypoderris Brownii. 



Sorus, with fringed indusium. 



Magnified 25 diameters. 



HYPOGLEL A family of Gasteromyce- 

 tons Fungi, characterized by their resem- 



Fig. 356. 



Hydnangium c .indicium. 



Basidiospores upon the hymenium. 



Magnified 400 diameters. 



Fig. 357. 



Hysterangium clathroides. 



Section of hymenium with oval basidiospores. 



Magnified 400 diameters. 



blance to the Truffles ( Ascomycetes) in grow- 

 ing underground, and by their fleshy mde- 



hiscent sporange, which is excavated into sinu- 

 ous cavities lined with basidiospores, which 

 are sometimes smooth and sometimes tuber- 

 culated (figs. 356, 357). 



BIBL. Tulasne, L. R. & C., Fungi Hypo- 

 gcei, Paris, 1851 ; " Rapport " on that work, 

 Ann. des Sc. nat. 3 ser. xv. 267, and Ann. 

 Nat. Hist. 2 ser. vol. viii. 19. 



HYPOPTERYGIACExE. A family of 

 Pleurocarpous Mosses with a peculiar ar- 

 rangement of the leaves, which are placed 

 in two opposite straight rows united on the 

 upper side of the stem, with a third median 

 row of smaller stipuliform leaves on the 



Fig. 358. 



Fig. 359. 



Hypopterygium . 



Fig. 358. Natural size. 



Fig. 359. A leafy branch. Magnified 5 diams. 



under side, bearing a resemblance to the 

 intermediate leaves in Selaginella (figs. 358 & 

 359). The cells of the leaves are parenchy- 

 matous and equal in all parts. The genera 

 are all exotic, viz. Hypopterygium, Cyatho- 

 phorum and Helicophyllum. 



HYPOPUS, Dug. A supposed genus of 

 Arachnida, of the order Acarina, and family 

 Acarea. 



Char. Body ellipsoidal, coriaceous ; palpi 

 absent; labium oblong, prolonged in the 

 form of a rostrum, and furnished with two 

 long anterior rigid setse. The species are 

 numerous, and are found as parasites upon 

 both animals and plants; as Arvicola (the 

 field-mouse), Bombus (the humble-bee), 

 Musca (fly), some Myriapoda; also upon 

 ferns, &c. Dujardin has rendered it pro- 

 bable that they are young forms of Gamasus. 

 They have no mouth nor digestive organs. 



PL 2. fig. 15 represents a Hypopus mus- 



z 



