PELL1E.E. 



[ 495 ] 



PENICILLIUM. 



parted; lobes torn. Perigone herbaceous, 

 tubular, the mouth denticulated. Arche- 

 gones eight to twenty. Epigone persistent, 

 torn at the summit. Sporange 4-valved. 

 Antheridia dorsal, placed on the rib, covered 

 by dentate incumbent leaflets. 



II. FossoMBRONiA. Fructificatiou emer- 

 ging from the end of the rib below the apex 

 of the frond, at length dorsal. Perichaete 

 obconic-bell-shaped, the mouth crenate or 

 dentate. Perigone wanting. Archegones 

 few. Epigone persistent, torn at the sum- 

 mit. Sporange circumscissile. Antheridia 

 dorsal, situated on the rib, naked. 



III. Metzgeria. Fructification emer- 

 ging from the ventral side of the midrib of 

 the frond. Perichaete ventricose, at length 

 bipartite. Perigone none. Archegones few. 

 Epigone persistent, torn at the summit, 

 Sporange four-valved. Antheridia ventral, 

 placed on the rib, covered by incumbent, 

 dentate leaflets. 



IV. Aneura. Fructification emerging 

 from the ventral side, near the margin of 

 the frond. Perichaete short, lobed or torn. 

 Perigone wanting. Archegones few. Epi- 

 gone persistent, torn at the summit. Spo- 

 range four-valved. Antheridia immersed in 

 the back of special lobes of the frond. 



V. Pellia. Fructification emerging from 

 the dorsal side of the frond. Perichaete 

 short, somewhat cup-shaped, the mouth 

 lacero-dentate. Perigone wanting. Arche- 

 gones several. Epigone membranous, ac- 

 companied by a few sterile archegones, at 

 first, at the lower jDart. Sporange four- 

 valved. Antherids immersed in the sm-face 

 of the frond. 



YI. Blasia. Fructification at first im- 

 mersed in the rib of the frond, then emer- 

 ging from the apex. Perichaete and peri- 

 gone wanting. Epigone membranous, with 

 few sterile archegones, at first, scattered to- 

 ward the lowest part. Sporange fom'-valved. 

 Antherids immersed in the rib of the thallus, 

 more prominent below, and covered by 

 little dentate scales. 



VII. Targionia. Fructification sessile, 

 inferior, solitary and terminal to the frond. 

 Perichaete two-valved, splitting vertically. 

 Perigone wanting. Epigone delicate, per- 

 sistent, investing the sporange until matu- 

 rity, sometimes evanescent above. Spo- 

 range bursting by an irregular slit, or into 

 fragments. Antherids immersed in the rib 

 of the frond below, covered by papillae. 



BiBL. See the genera, and Hepati- 



CACE^. 



PELOPS, Koch (Acarina). — Is consoh- 

 dated with Galumna. 



PELTIDEA, Ach.— A genus of Parme- 

 liaceae (Gymnocarpous Lichens), charac- 

 terized by a foliaceous, usually leathery thal- 

 lus, with woolly veins beneath; the sub- 

 orbicular, shield-like apothecia arising on 

 the upper sides of the lobules. 



P. canina, a large Lichen, is extremely 

 common on the ground among moss in 

 woods. Two or three nearly allied species 

 are sejiarated from this by most authors, 

 but with questionable propriety. Three or 

 four others are subalpine. 



BiBL. Hook. Bn7. F/ora, ii. pt. 1. p. 218, 

 Eng. Bot. 2229. 



PELTIGERA, Hofi-m. = Species of Pel- 

 TiDEA and Sticta. 



PENICILLIUM, Link.— A genus of Mu- 

 cedines (Hyphomycetous Fungi), of which 

 the s])ecies P. glaucum is at once one of the 

 most frequent and the most puzzling plants of 

 the class. This fungus is the commonest of 

 the constituents of the greenish or bluish 

 mould formed on decaying vegetable sub- 

 stances of all kinds, especially on semifluid 

 or liquid matters. On the surface of liquids 

 it forms a kind of dense pasty crust, slimy 

 on the lower surface, and coloured and pul- 

 verulent (bearing spores) above. When the 

 upper fertile layer is examined under the 

 microscope, it is found to consist of pedicels 

 terminating in a repeatedly but shortlv bi- 

 furcated pencil, each ultimate branch of 

 which bears a moniliform row of spores 

 (the ramification of the pedicels is not di- 

 stinctly represented in fig. 562, but the ap- 



Fig. 562. 



Penicillium. 



A fertile plume with pencils of spores. 



Magnified 200 diameters. 



pearance of the spores is characteristic). 

 The mode of attachment of the spores is 



