PELOPS. 



PENICILLIUM. 



Char. Unattached ; feet cylindrical ; ori- 

 fices without rays, on two equal approximate 

 warty eminences at the anterior end. They 

 live buried in mud. Two species,: 



P. corrugata. Test deep brown, much 

 elongated, rudely wrinkled transversely. 



P. fflabra. Test greenish yellow, smooth, 

 pilose, shorter than the last. See TUNI- ; 



CATA. 



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

 43. 



PE'LOPS, Koch (Acarind). Differs i 

 from Oribata in the hairs on the vertex | 

 being flat or spatula-shaped. (Murray, EC. \ 

 Ent. 218 ; Michael, Jn. Mic. Soc. 1879, 237.) I 



PELOPSI'NA, Brady. A genus of Are- | 

 naceous Foraniinifera, one- or inany-chani- 

 bered ; walls thick, composed of mud, with 

 a long chitinous neck. Living, South Seas. 

 (Brady, Qu. M. Jn. 1870.) 



PELTIDE'A, Hofftn., = 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; tne suborbicular 

 shield-like apothecia arising on the upper 

 sides of the lobules. 



P. caninay 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 with questionable propriety. Three or 

 four others are subalpine. 



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

 Bot. 2229 ; Leighton, Lick. Flor. 101. 



PENEROP'LIS, Lamk. A genus of 

 Porcellaneous Foraniinifera. 



Broad, complanate, and ear-shaped (P. 

 pertusm, PI. 23. fig. 11), or narrow, subcy- 

 lindric, and crosier-like (Spirolind) (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 circle, 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) j and divided 

 into rows of holes, 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 ofMu- 

 cedines (Hyphomycetous Fungi), of which 

 the species P. f/laucum 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 

 pulverulent (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 

 shortly bifurcated pencil, eacli ultimate 

 branch of which bears a moniliforni row of 

 spores. The ramification of the pedicels is 

 not distinctly represented in fig. 557 ; but the 

 appearance of tne spores is characteristic ; 

 and the ramifications of the sporophores are 

 scarcely perceptible in examples growing on 

 dryish substances. The mode of attach inn it 

 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, greenish, or bluish, according to 

 age : under the microscope they appear 

 opaque when mature. 



So far there is little difficulty about the 

 history of these plants j and if the spores of 

 the above form are sown on a glass slide, 

 kept moist with an organic 

 liquid, they will germinate 

 and ramifv, and under fa- 

 vourable circumstances bear 

 thin penicillate tufts of spores 

 at points which emerge from 

 the nutrient liquid. But 

 this same fructification of 

 P. fflaucum presents itself 

 invariably under certain cir- 

 cumstances associated with 

 the vinegar-plant and the 

 yeast-plant, toward the 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 followed in 

 all cases by the appearance 

 of crusts of Penicillium- 

 mould on the upper surface, 

 whence it would appear that 

 the vinegar-plant was only the mycelium of 

 Penicillium. It was asserted, moreover, 



Fig. 557. 



Penicillium. 



A fertile plume 

 with pencils of 

 spores. 



Magnified 150 

 diameters. 



