of 



549 



which is often met with in some vegetable 

 infusions ; and, under the microscope, ap- 

 pears to consist of a mass of gray-looking 

 jelly, a film that can change its form at 

 will, and assume every diversity of outline. 

 Sometimes, as is stated by Mr. Rymer Jones, 

 you will find it shrunk up into a gelatinous 

 ball, then shooting out rays in all directions, 

 which appear like limbs, or moulding itself 

 into any form adapted to the shape of ani- 

 malcules it may choose to swallow for its 

 food. 



PSEUDOTETRAMERA. The third 

 general section of the Coleoptera, comprising 

 those beetles which have the tarsi apparently 

 four-jointed, although in reality consisting 

 of five joints, the fourth being so exceedingly 

 minute as to have escaped the notice of the 

 tarsal systematists, who gave to these in- 

 sects the sectional name of Tetramera. The 

 whole of them feed upon vegetable matter, 

 and are found in their perfect state upon 

 flowers, leaves, or the bark of trees : the 

 larva are fleshy grubs. Latreille divides 

 this section into seven groups or families 

 the Rhyncophora (Curculio) j Xylophaga 

 (Scolytus, &c ) ; Platysoma (Cucujus) ; 

 Longicornes (Cerambyx) ; Eupoda (Crio- 

 ceres) ; Cyclica (Chrysomela) ; and Clavi- 

 palpi (Erotylidae). 



PSITHYRUS. A genus of Hymenop- 

 terous insects belonging to the family Apidce. 

 Until lately the insects of this genus were 

 confounded with the Humble-bees (Bombus), 

 which in many respects they nearly resemble, 

 but differ widely from them in others ; viz. 

 they make no nests of their own, neither 

 do they collect food for their young, but, 

 like the cuckoo among birds, they deposit 

 their eggs in the nests of others, and leave 

 their young to be hatched and reared by 

 them. They may be distinguished also from 

 the Bombi by the structure of their hinder 

 legs, the tibia being narrower and covered 

 throughout with hair. 



PSITTACID^E. The name of a tribe 

 of Scansorial Birds, of which the_ Parrot 

 is the type. They are characterized by 

 their short, hard beaks, which^are generally 

 highly arched, and surrounded at the base 

 by a naked skin, in which are the orifices 

 of the nostrils. They are natives of tropical 

 and the warmer temperate regions ; and 

 they subsist for the most part upon fruits, 

 seeds, honey, &c. Parrots, Macaws, Cock- 

 atoos, &c., are included in this numerous 

 family. [See PARROTS, &c.] 



PSOCIDjE. A family of minute Neurop- 

 terous insects, which frequent the trunks of 

 trees, palings, old walls, moss-covered stones, 

 old books, &c. for the purpose of feeding, 

 either upon the still more minute animalcule 

 which inhabit those situations, or upon the 

 decaying vegetable matter to be there met 

 with. The eyes are semiglobose, lateral, 

 and prominent ; the ocelli are three in 

 number, and placed triangularly between the 

 eyes ; the antennae are slender and setaceous; 

 the body is gibbose, ovate, and short ; the 

 meso- and meta-thorax larger and deeply 

 impressed ; the wings are hyaline, deflexed, 



with conspicuous veins, the anterior larger 

 than the posterior, and often variegated and 

 coloured ; legs long and slender. These 

 insects are remarkably active, and when 

 approached they quickly endeavour to hide 

 themselves by running to some obscure place. 

 Towards the end of summer the perfect 

 insects sometimes appear in great numbers. 

 The larva differs from the imago in being 

 apterous, while the pupa has rudimental 

 wings. 



PSOPHODES. A genus of birds belong- 

 ing to the family MeliphagUke ; it contains 

 the PSOPHODES CREPITAJJS, or COACH-WHIP 

 BIRD. This is a shy and recluse bird, 

 peculiar to South Australia, and renowned 

 for the singularity of its note, which is loud 

 and full, ending sharply like the cracking 

 of a whip whence its name. It rarely 

 exposes itself to view, but keeps in the 

 midst of the densest foliage and among the 

 thickest climbing plants, through which it 

 threads its way with the utmost ease. Its 

 actions are always animated and sprightly, 

 but particularly so in the spring, when the 

 males may often be seen chasing each other, 

 while they make the brushes ring with their 

 clear and voluble song, or rather whistle. 

 The male has the head, ear-coverts, chin, 

 and breast black ; on each side of the neck 

 is a large patch of white ; all the upper 

 surface, wings, flanks, and base of the tail- 

 feathers olive-green : the remaining portion 

 of the tail-feathers black.the three lateral fea- 

 thers on each side tipped with white ; under 

 surface olive brown ; bill black ; feet reddish - 

 brown. The female may be distinguished 

 by her more obscure plumage and smaller 

 size. The food consists of various kinds of 

 insects, mostly obtained from the ground 

 by scratching up the leaves and turning over 

 the small stones. Besides its peculiar shrill 

 song, an idea of which it would be difficult 

 to convey in words, it possesses a low in- 

 ward song of considerable melody. 



FSYLLA : PSYLUD-fl3. A genus and 

 family of Homopterous insects, similar in 

 their general habit, as well as in their 

 saltatorial powers and deflexed wings, with 

 some of the Cicadce. They subsist in all 

 their states upon plants, and have received 

 specific names from the various trees and 

 vegetables which they frequent. Their 

 larvae have the body very flat, the head 

 broad, and the abdomen rounded behind ; 

 the pupae are distinguished by having four 

 large and broad scales on the back, which 

 are the rudimental wings. Many species 

 in the preparatory stages are covered with 

 a white cottony secretion, and their excre- 

 ment forms threads or masses of a gummy 

 sucreous nature. Some species also, by 

 puncturing vegetables, in order to suck the 

 sap, produce gall-like monstrosities, es- 

 pecially upon the leaves and buds. Two 

 species, Psylla pyri and Chemies mali, are 

 very injurious in orchards, the former to the 

 young shoots and leaves of the pear, and the 

 latter to the apple. 



PTARMIGAN. (Lagojnts muttis.} This 

 bird, which is also called White Grouse, is 



