504 



PTERONIA-PULEX. 



same size as the preceding, and the chief difference 

 between them consists in the colour, the upper part 

 being grey, the under part whitish, and there are 

 long stiff hairs on the cheeks and sides of the head, 

 which appear to serve as organs of touch in the living 

 animal. 



S. Siberians, the common flying squirrel, is a native 

 of the forests in the colder parts of Europe and Asia. 

 Its residence is in the pine forests, and it is not rare 

 in Sweden, Finland, the wooded tracts to the east of 

 the Baltic, and so on eastward through Russia and 

 Siberia. Its colours are ashey grey on the upper 

 part and white on the under ; its tail is broad, and 

 only about half the length of the body ; and the 

 lateral membrane, instead of forming a sharp angle 

 behind the rest, forms a simple lobe. It jumps with 

 great alacrity, and very seldom misses its hold or falls 

 to the ground ; it is a lively little animal, and far 

 from being the least interesting inhabitant of those 

 dreary forests in which it resides. It has sometimes 

 been confounded with the North American species, 

 but they are perfectly distinct. In Cuvier's arrange- 

 ment it is very properly taken as the typical animal 

 of the sub-division. The name given to it by the 

 Russians, who capture it in great numbers as a fur 

 animal, is polatuca, which name was Frenchified by 

 Buffou, and applied to the American species. 



S. volucella. This is the American one, found 

 abundantly in the wooded parts of the United States, 

 where the animals associate in little companies, and 

 give much liveliness when they are put in motion. 

 They live upon fruits, seeds, and the buds of plants. 

 It is a very small animal, not above five inches long 

 in the body, or two and a half in the tail. Its 

 colours are reddish grey above and white below. It 

 is a lively little animal when in motion, but its chief 

 time for activity is during the night. When kept ia 

 a cage it generally sleeps at the bottom during the 

 day, but skips and frisks about with restless activity 

 after night begins to set in. It does not appear that 

 America contains any more than this one species. 



PTERONIA (Linnaeus). A genus of evergreen 

 shrubs, found at the Cape of Good Hope. The 

 flowers are syngenesious, and belong to Compositce. 

 They are easily managed greenhouse plants. 



PTEROPHORIDjE(PTEUopHORiTRS,Latreille; 

 ALUCITID^E, Leach). A family of small nocturnal 

 lepidopterous insects, distinguished from all other 

 lepidopterous insects, by having the four wings, or two 

 at least, slit longitudinally from the extremity to the 

 base, and resembling branches or fingers, and deeply 

 fringed, so as to have the appearance of feathers, 

 whence these insects have obtained the names of 

 plume moths. Their caterpillars are sixteen-legged ; 

 they feed upon leaves of various plants, and do not 

 construct rases, like some of the Tineuke. The 

 body of the perfect insect is long and narrow, and 

 their legs very long, so that many of the species 

 (composing the genus Ptcrophorus] have so much the 

 appearance of Tlpute* that De Geer called them 

 Phalencs-tipiila:. The genera are Agdistes, Ptero- 

 phorus, and Orneodes (or Alncita). In the first, con- 

 sisting of a single species, the wings are entire, but 

 the whole appearance of the insect of which it is 

 composed is so similar to that of the true Pterophm-i, 

 that it must evidently be placed in the family. In 

 Ptcrophorus (Aludta pentadactyla, Linnaeus, &c.) the 

 upper wings are divided into two branches, and the 

 posterior into three ; whilst in Orneodes (jlucita 



hexadacly'a, Linnaeus), the wings are divided into six 

 leathers. 



PTEUOPODA is the second family of the third 

 order Cyolobranckiata of modern nialucologists. It 

 includes the genera Alulanta, Spiratella, and the 

 itcver-to-be-delcrniincd inhabitant of the AIIGONAUTA. 

 Sec that article. The name of this genus is derived 

 from an aliform appendage on each side of the 

 animal's body, assisting its natation after the fashion 

 of oars. The shells themselves are always symmetrical, 

 extremely thin, semi-transparent, and longitudinally 

 rolled from the apex forward, the evolutions being on 

 the same plane. 



PTEROSTYLIS (Dr. Brown). A genus of Now 

 Holland Orchidecc, introduced into our collections 

 within these last twenty-five years. They succeed 

 best in a frame, and in peat earthy soil, requiring only 

 to be protected from frost. 



PTEROTRACHEA (Lamarck). A naked mol- 

 lusc, inhabiting the seas of hot climates. This genus 

 at present only contains marine carnivorous molluscs, 

 described by Semur, and it is not by any means suffi- 

 ciently well defined to follow his arrangement without 

 a further knowledge of them. 



PTINIDvE (Leach). A family of coleopterous 

 insects, belonging to the section Pentatnera and sub- 

 section Sen-iconics, having the antennjc nine or 

 eleven-jointed, sometimes pectinated or serrated, or 

 in some species terminated by three large joints, not 

 forming a solid club. The mandibles are short and 

 triangular, the head short and rounded, or nearly 

 globose, and hidden from above by the thorax, which 

 is high and hood-like ; the body is generally ovoid- 

 cylindrical, convex above, and of a solid consistence. 



The genera of which this family is composed are 



1. Antennae uniform and simple. Ptinus, Gibbium, 



and Jlfi'zium. 



2. Antennae uniform, pectinated, or strongly ser- 



rated. P lilinus, Xyletinus, and Oc/tina. 



3. Antennas terminated by three large joints. 



Dorcatoma, Anobium, and Dryophilus. 



These insects reside in old wooden erections or 

 furniture, upon which the larvae feed, boring through 

 them in circular holes. These larvae very nearly re- 

 semble those of the Scarabfcida-, the body being 

 fleshy and curved ; they construct a cocoon with the 

 fragments of wood which they have been gnawing, 

 and therein undergo their transformations. The 

 perfect insects counterfeit death, when alarmed, by 

 lowering the head, withdrawing the legs and an- 

 tenna?, and falling to the earth. Their ordinary 

 movements are slow, and they seldom make use of 

 their wings. The best known genus is that of Ano- 

 bium, which comprises the insects commonly named 

 the DEATH-WATCH (which see). 



The genus Ptinus is distinguished from the other 

 genera with simple antennae, by the ovoid-cylindrical 

 form of the body, and the insertion of the antennae 

 between the eyes. There are eight or nine British 

 species, all of which are of small size. 



PULEX (Linnaeus). A genus (or rather PULI- 

 CID^E, a family) of apterous insects, forming the order 

 Aphunaplera of Kirby (Siphonaptera, Lwtreiile), con- 

 sisting of the various species of fleas. It is certainly 

 a circumstance of some singularity that the throe 

 troublesome genera, Pediculuf, (Jimcjc, and Pnle.v, 

 consisting of the lice, bug, and flea, should, both in a 

 natural-history point of view, and with reference to 

 their peculiar organisations, and consequent classifi- 



