393 



POCHARD. 



PCECILOPODA. 



394 



1 3 2 



Plumbago capenta. [Pi.i MHAUINACE,*:.] 



1, a flower deprived of corolla and stamens ; 2, the ovary and stamens inr- 

 rounding it ; S, a vertical lection of the ov.ary, showing the peculiar position of 

 the ovule. 



keeled, unarmed ; the styles terminal. The species of thin genus are 

 very numerous, constituting the commonest weeds that follow the 

 migrations of man, aud generally containing a sufficient quantity of 

 nutritive matter to render them fodder for various animals. Thirteen 

 species of this genus are described by Babington as natives of the 

 British Islands. Of these the most common are the P. annua and 

 P. pratenrit. The former is perhaps the commonest of British plants, 

 springing up on every neglected spot around the habitations of man. 

 The latter is known by the name of the Smooth-Stalked Meadow-Grass, 

 and is found in most pasture lands. P. nemoralis, the Wood Meadow- 

 Grass, is also a common grass in shady places. Many of the recent 

 genera of Grasses were formerly referred to the genus Poa. 



POCHARD. [DUCKS.] 



POCILLO'PORA. [MADREPOR.EA.] 



PODA'RCIS, a genus of Lizards. 



PODA'RGUS. [GOAT-SUCKERS.] 



PO'DICEPS. [C'OLYMBID*.] 

 PODICEPSl'NjE. [COLYMBID-E.] 



PODINE'MA, a genus of Lizard?. 



PO'DOA. 



PODOCARPUS. 



PODOCES. 



PO'DOPHIS. 



PODOPHTHALMATA, or PODOPHTUALMIA. [CIXSTACEA.] 



PODOPHTHA'LMUS. [POKTINIM.] 



PODOPHY'LLACE^K, a small group of Polypetalous Exogenous 

 Haute, by some regarded aa a distinct natural order, and by others 

 referred to Ranunculacta as a section. They would be Papaveraceous 

 plants if they had consolidated carpels ; but possessing no more than 

 one carpel, they appear more referrible to Kanunculacea, from which, 

 in fact, they seem to differ in having a solitary carpel, which however 

 also occurs in that order, although not characteristic of it. The only 

 species referred to 1'odophyllacetx are Jtffersonia and Podophyllum, two 

 North American plants, with succulent acrid root-stocks, deeply lobed 

 leaves, and white- flowers hidden among them. They have 3 or 4 

 sepals, twice as many petals, indefinite hypogynous stamens with 

 linear or oval anthers, a thick sinuous stigma, and the ovules arranged 

 along the central suture of the solitary carpel. Podophyllum peltatum, 

 or May-Apple, is not uncommon in gardens, whither it has been 

 introduced from the United States, where it is employed as a safe and 

 dive cuthartic. 



V. 



Podophyllum peltatum. 



1 , a flower ; 2, a carpel ; 3, a transverse section of the same ; 4, a vertical 

 section of a seed. 



PODOPSIS. [SPONDYLID.K.] 



PODOSTEMA'CE^E, Podottemadi, an obscure natural order ot 

 tropical submersed aquatic Plants, with minute incomplete flowers. 

 They appear to have no very obvious relation to any other natural 

 group, and are little known even to botanists except by name. They 

 however are certainly Exogens, and probably allied to Urticacece and 

 J'ljH rtHxtr: Endlicher places them among his aquatic class, consisting 

 of Ceratophyllece, Callitrichinece, and Podoatemece, and enumerates seven 

 genera. % 



PCECILASMA. [CIRRIPEDIA.] 



PCECILONITTA, a genus of Ducks. [DOCKS.] 



PCECILO'PODA, M. Latreille's name for his sixth order of Crus- 

 tacea, and arranged by him under his second sub-class, Entoinostraca. 

 The following is M. Desmarest's character of the order : 



Head confounded with the trunk ; a shell, or the anterior of the 

 body in the form of a buckler ; mouth in the shape of a beak, or 

 composed of appendages which cannot be compared to mandibles; 

 antenna) short and simple or null ; eyes often distinct aud sessile ; 

 anterior feet terminated by one or two hooks, or by claws, fit either 

 for walking or prehension ; the posterior feet destined for natation, 

 either composed of or accompanied by branchial lamina;, or membra- 

 nous and digitated. 



1st Division. 



Mouth in form of a beak ; antenna? to the number of four ; twelve 

 feet, of which the first two are in the form of acetabula, or suckers 

 (ventouses). Family Argulida;, Leach. 



Argulus is the only genus of this division. 



2nd Division. 



Mouth in form of a beak ; antennas to the number of two only. 

 Family Caligidas, Leach. 



These, says M. Desmarest, like the last, are crustaceous aquatic 

 parasites ; the greater part of them are marine, adhering to the 

 branchia) aud the axilla: of fishes, having the antenna: inserted at the 

 external angle of two lobes on the anterior surface of their shell, and 

 the eyes most frequently not apparent. 



1st Subdivision or Race. 



Twelve feet ; the six anterior terminated by hooka or uuguiculated. 

 Extremity of the abdomen furnished with two bristle-like appendages 

 or oviferous tubes, which are cylindrical and elongated. 



The genera arranged by M. Desmarest under this subdivision are 

 Anthoioma, Leach (Caligut, Latr., Lam., Risso), and Dicheltatium of 

 Hermann the younger and authors. 



