PSAMMOSP1LKKA. 



PSILOTE^E. 



organized materials, as carbonic acid and 

 ammonia. The other, that animals absorb 

 oxygen and evolve carbonic acid, while 

 plants evolve oxygen, cannot be applied 

 generally in the case of these microscopic 

 organisms. But certain Protozoa have no 

 mouth, and cannot admit food-particles like 

 Amoeba, nor can organic matters be eudos- 

 mosed by them. Movement has in late 

 years been shown to be a property of proto- 

 plasm, limited where a cell-wall is present, 

 yet it may be said to be universal. Stein 

 and Kent consider the presence of a contrac- 

 tile vesicle to form a distinctive- character ; 

 but its existence in Volvox, we think must 

 invalidate this view. 



The chemical property of the protoplasm, 

 that of animals swelling and dissolving in 

 solution of potash or ammonia, while that 

 of plants is apparently unaffected, has also 

 been called in aid ; and this really appears 

 to be the best individual test. Little atten- 

 tion has been paid to this part of the question, 

 so that the older views must remain, until 

 further experiments have been made. See 

 ANIMAL KINGDOM, and the heads of the 

 Classes. 



BIBL. Siebold, Vergl. An. i. ; Koch, Icon. 

 Hut. 1865 ; Gabriel, Gegenlaurs Morph. 

 Jahrb. 1875 ; Mereschowski, Russl. Arch, 

 mik. An. 1878, xvi. ; Butschli, fironn's Xlass. 

 #c.; Kent,/*/. 1880,31. 



PSAMMOSPILE'RA, Schultze. An 

 Arenaceous Foraminifer, round, free or 

 attached, made of coarse sand-grains and 

 fine cement ; common in deep seas. (Brady, 

 Qu. Mic. Jn., new ser. xix. 8.) 



PSECA'DIUM, Reuss. A globose or 

 Glanduline Marginulina. Fossil. 



BIBL. Reuss, Sits. Ak. Wien, xliv. 368. 



PSEUDOCALA'NUS, Boeck. A genus 

 of marine Copepoda. 2 sp. (Brady, Copep., 

 Ray Soc. i. 44.) 



PSEUDOCH'LAMYS, Clap, et Lach. 

 A genus of Arcellina (Rhizopoda). P. ni- 

 tella ; carapace brown, pseuaopodia broad 

 and short ; in ponds. (Claparede et Lachm. 

 Inf. 443.) 



PSEUDOC YC'LOPS,Brady. A genus of 

 rnarineCopepoda. 2sp. (Brady, Co/we, i. 81.) 



PSEUBOCYTH'ERE, G. O. Sars. One 

 of the Cytherida-, valves very thin, obliquely 

 quadrangular ; five joints in upper, seven in 

 lower antennae, which are long and have 

 long setaB ; no eyes. 1 British species. 



BIBL. Brady, Linn. Tr. xxvi. 453. 



PSEUDODIFFLUGIA, Schlurn, A 

 genus of Arcellina. 



Char. Shell membranous, ovoid or ovo- 

 globular, smooth or striped spirally, with a 

 wide round opening whence issue pseudo- 

 podia. (Pritchard, Infusoria, p. 557.) 



PSEUDOGON1DIA A term applied to 

 bodies appearing in the interior of cells of 

 Algae, which are obscure in their nature, 

 being either metamorphosed and isolated 

 masses of protoplasm, or parasitic bodies 

 resembling monads. They are apparently 

 connected with the objects called CHYTIU- 

 DIUM and PYTHIUM. (Cienkowski, Prinys- 

 heim's Jahrb. Sot. i. 371.) 



PSEUDOG'RAPHIS, Nyl. A genus of 

 Microlichens parasitic on Lecanorae. 



Char. Spores colourless or becoming 

 brown, 4-6-locular, sometimes becoming 

 submuriform ; slightly blue with iodine. 



BIBL. Lindsay, Qu. Mic. Jn. 1869, 352. 



PSEUDOPO'DIA are the processes of 



Ctoplasm which are protruded from the 

 ies of the RHIZOPODA, serving for loco- 

 motion and the prehension of food. 



PSEUDOS'PORA, Cien. A genus of 

 Flagellate Infusoria. Body naked, swimming 

 or creeping; flagella two, equal ; no mouth. 

 P. volvoets, on and in Volvox: length 

 1-1250". (Kent, Inf. 304.) 



PSEUDOSPORES. The apparent 

 spores of Uredinei and Tremellini, which 

 germinate and produce the real reproductive 

 spores, which are then called spuriola. 



PSICHOHOR'MIU M, Ktz. This genus 

 consists of species of Conferva, whose iila- 

 ments are more or less incrusted with oxide 

 of iron or carbonate of lime. 



BIBL. Rabenh. Fl. Evr. Alg. iii. 324. 



PSILO'NIA, Fr. A genus of Sepedoniei 

 (Hyphomycetous Fungi), consisting of little 

 compact tufts of twisted filaments, at 

 first covering the fusiform, globose, or oval 

 spores, which arise from the wart-like pro- 

 tuberances on the central filaments, and 

 soon become free. They are found on dead 

 w r ood or on reeds. P. nivea, which is com- 

 mon on the bark of beech-trees, is the 

 product of an insect, AdeJgesfagi. 



BIBL. Berk. Br. Fl. ii.'pt. 2. 353 ; Ann. 

 N. H. 2. viii. 179 ; Fries, Sum. Veg. 495. 



PSILOTE^E. A family of Lycopodia- 

 ceous plants, distinguished by their many- 

 celled sporanges, varying much in habit and 

 external appearance. 



Synopsis of Genera. 



Psilotum. Sporanges sessile, three-celled, 

 busting imperfectly into three valves by a 

 vertical crack, filled with mealy spores. 



