PELOPS. 



[ -"^84 ] 



PENICILLIUM. 



Char. Unattached ; feet cylindrical ; ori- 

 fices ^^-itll0^lt rays, on two equal approximate 

 warty eminences at tlie anterior end. They 

 live buried in mud. Two species^ 



P. corrugata. Test deep brown, much 

 elongated, rudely wrinkled transversely. 



P. (glabra. Test greenish yellow, smooth, 

 pilose, shorter than the last. See Tuni- 



CATA. 



BiBL. Forbes and Hanley, Br. Moll. i. 

 43. 



PE'LOPS, Koch (Aearina). — Differs 

 from Oribaia in the hau'S on the vertex 

 being flat or spatula-shaped. (Murray, Ec. 

 Ent. 218; Michael, Jn. itfjc/Soc. 1879, 237.) 



PEI.OPSI'NA, Brady,— A genus of Are- 

 naceous Foraminifera, one- or many-cham- 

 bered ; Willis thick, composed of mud, with 

 a long cliitinous neck. Living, South Seas. 

 (Brady, Qti. M. Jn. 1879.) 



PELTIDEA, noto., = Species of Pel- 

 TiGERA and Sticta. 



PELTID'IUM = Alteutha. 



PELTIG'ERA, Willd. — A genus of 

 Parmeliaceous Lichens, characterized by a 

 foliaceous, usually leathery thallus, with 

 woolly veins beneath ; the suborbicular 

 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 separated from this by most authors, 

 but wnth questionable propriety. Three or 

 four others are subalpine. 



BiBL. Hook. Br. Fl. ii. pt. 1. 218; Eny. 

 Bot. 2229 ; Leio-hton, Lich. Flor. 101. 



PENEROP'LIS, Lamk.— A genus of 

 Porcellaneous Foraminifera, 



Broad, complanate, and ear-shaped (P. 

 jjertusns, PL 23. fig. 11), or narrow, subcy- 

 lindric, and crosier-like (Spiroluia) (S. 

 austriaca, PI. 23. fig. 12) ; striated. The 

 primordial double chamber is succeeded by 

 curved chambers in one direction ; and as 

 these vary in transverse extent, sometimes 

 to even three fourths of a cii'cle, the shell 

 takes different shapes. The aperture is 

 single and lobulate in the early chambers ; 

 cribrate in the narrow, branched in the 

 nautiloid forms {Dendritina) ; and divided 

 into rows of lioles, often tubular, in the 

 outspread varieties. Living in the Medi- 

 terranean and warm seas only ; fossil in the 

 Tertiaries. 



BiBL. Williamson, Rec. For. 45 ; Parker 

 and Jones, Ann. N. H, 3. v. 179 ; Car- 

 penter, Phil. Tr. 1859, 2 ; Foram. 84. 



PENICIL'LIUM, Link.— A genus of Mu- 

 cedines (Hypliomycetous Fungi), of which 

 the species P. f/laueitni 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 

 pidverulent (bearing spores) above, ^^'hen 

 the upper fertile layer is examined under 

 the microscope, it is found to consist of 

 pedicels terminating in a repeatedly but 

 shortly bifurcated pencil, each ultimate 

 branch of which bears a moniliform row of 

 spores. The ramification of the pedicels is 

 not distinctly represented in fig. 557 ; but the 

 appearance of the spores is characteristic ; 

 and the ramifications of the sporophores are 

 scarcely perceptible in examples growing on 

 dryish substances. The mode of attachment 

 of the spores is shown in figs. 15 and 16 of 

 PI. 26. The mycelium consists of inter- 

 woven articulated filaments, most exten- 

 sively ramified. The spores appear whitish, 

 yellowish, gi-eenish, or bluish, according to 

 age : under the microscope they appear 

 opaque Avhen mature. 



So far there is little difli cully about the 

 history of these plants ; and if the spores of 

 the above form are sown on a glass slide, 

 kept moist with an organic 

 liquid, they will germinate 

 and v,imify, and under fa- 

 vom-able circumstances bear 

 thin peniciUate tufts of spores 

 at points which emerge from 

 the mitrient liquid. But 

 this same fructification of 

 P. f/laticum presents itself 

 invariably under certain cir- 

 cumstances associated with 

 the vinegar-plant and the 

 yeast-plant, toward tJie close 

 of the ordinary development 

 of these fungi. In common 

 with most observers, we find 

 that the exhaustion of the 

 saccharine matrix of the 

 vinegar-plant is 1 olio wed in 

 all cases by the apjiearance 

 of crusts of Penicillium- 

 mould on the upper surface, 

 whence it woidd appear that 

 the vinegar-plant was only the mycelium of 

 Fenicillium. It was asserted, moreover, 



Fig. 557. 



Penicillium. 



A fertile plume 

 with pencils of 

 spores. 



Magnified 150 

 diameters. 



