popular 23tctt0navi? at &mmatetf feature. 529 



PLAICE. (Pfetironectcs platessa.^ This 

 well-known species of Plewonectidce, or 

 Flatfish, is easily distinguished from others 

 of the genus by its shape and colours, being 

 | very broad and flat, and of a fine pale brown 

 above, marked both on the body and fins by 

 numerous moderately large orange-coloured 

 spots ; while the whole of the under part is 

 perfectly white : behind the left eye is a 

 row of six tubercles, reaching as far as the 

 commencement of the lateral line ; the 

 mouth is rather small, the lower jaw longer 

 than the upper, and both furnished with a 

 row of small teeth. When near the ground 

 they swim slowly and horizontally ; but if 

 suddenly disturbed, they sometimes change 



the horizontal to the vertical position, dart- 

 ing along with meteor-like rapidity, and 

 then again quickly resuming their inactive 

 habits at the bottom of the water. Plaice 

 feed on small fish and young Crustacea, and 

 have sometimes been taken on our coasts 

 weighing fifteen pounds, but a fish one-half 

 that weight is considered very large. The 

 finest kind, called Diamond Plaice, are 

 caught on the Sussex coast. These fish are 

 in considerable esteem as food, though by 

 no means equal to the Turbot and Sole. 

 Those of a moderate size are reckoned the 

 best eating. 



PLANAXIS. A genus of Mollusca, re- 

 sembling the Phasianelhe, very abundantly 

 found in India, South America, and the Isle 

 of France. The shell is small and oval, the 

 spire consisting of few whorls ; outer lip 

 thickened and denticulated within ; oper- 

 culum thin and horny, with a terminal 

 nucleus. 



PLANIPEXNES. The name given to a 

 tribe of Neuropterous insects, comprehend- 

 ing those in which the inferior pair of wings 

 almost equal the superior ones, and are 

 simply folded underneath at their anterior 

 margin. The antenna are multi-articulate, 

 and much longer than the head ; the max- 

 : illary palpi are shorter than the head, and 

 I are composed of four or five joints. The 

 I Ant-Lions (Myrmcleon) and Termites are 

 examples of this tribe. 



I PLANORBIS. A genus of snails, chiefly 

 inhabiting ponds or the banks of rivers, and 

 deriving their name from the form of the 

 shell, which is that of a flattened orb, occa- 

 sioned by the volutions being coiled on the 

 same plane. Many of the species are com- 

 mon in Great Britain ; and fossil species are 



found in the freshwater strata of the Isle of 

 Wight, and in the neighbourhood of Paris. 



(P. OOAUALODfENSlS.) 



PLANTIGRADA. (Lat. planta, the sole 

 of the foot ; graflior, I march.) The name 

 of a tribe of carnivorous Mammalia, which 

 apply the whole or part of the sole of the 

 foot to the ground in walking, &c. The 

 Boars, Racoons, Badgers, &c. are examples 

 of Plantigrade Carnivora. 



PLANT-LICE. [See APHIS.] 



PLATESSA. A sub-genus of the Pleu- 

 ronectula;, or flat-fish family, comprising the 

 Flounders, Plaice, &c. 



PLATYCERCUS. A genus of the Parrot 

 tribe, which derives its name from its fine 

 wide tail : there are many species, most of 

 which are natives of Australia. As an ex- 

 ample, we may cite the PENNAXTIAN or 

 BLUE-CHEEKED PARRAKEET (Platycercw 

 Pennantii). This beautiful Parakeet is very 

 generally dispersed over New South Wales, 

 its true habitat, and is chiefly found on the 

 ranges of grassy hills and brushes. Although 

 much variation exists between the plumage 

 of these birds in youth and maturity, the 

 colouring of the sexes when fully adult is 

 alike. " The head, neck, all the under sur- 

 face, the rump and upper tail-coverts, are of 

 a rich deep crimson-red ; the feathers of 

 the back and seapularies black, broadly mar- 

 gined with rich crimson-red ; the cheeks and 

 shoulders cerulean blue ; the greater wing- 

 coverts pale blue ; the primaries and secon- 

 daries black, with the basal half of their 

 external webs margined with deep blue ; 

 the two centre tail-feathers green, passing 

 into blue on their margins and at the tip ; 

 the remainder black on the inner webs for 

 three-fourths of their length ; deep blue for 

 nearly the same length on their outer webs, 

 and largely tipped on both webs with pale 

 blue, which becomes still paler to the tips of 

 the feathers ; bill horn-colour ; irides very 

 dark brown ; feet blackish brown." It 

 I breeds in the holes of the large gum-trees ; 

 the months of September, October, and No- 

 vember constituting the breeding season. 

 It makes no nest, but deposits from four to 

 seven white eggs on the rotten wood at the 

 bottom of the hole. In disposition this 

 species is tame and familiar ; few can ex- 

 ceed it in interest or beauty ; and conse- 

 quently it is one of the commonest living 

 Parakeets sent from Australia to this 

 country. The plumage of the young birds 



