520 



Crratfttrj? of Natural y& 



to swim, but, I think, without help would 

 soon have been drowned." 



PHYLLIDEA: PIIYLLIDID^E. A 



genus and family of Mollusca, generally 

 found adhering to rocks, buildings washed 

 by the sea, or other marine objects ; and 

 which, though of a dull colour outside, are 

 often very beautiful in the interior. Some 

 of the species differ from all other univalves, 

 in being composed of movable pieces at the 

 back, formed to facilitate the motion of the 

 animal. Some are particularly simple in 

 form, the shape being no more than that of 

 a conical cup or deep dish ; others are boat- 

 shaped ; and, when fixed, so fast do they 

 retain their situation, by exhausting the air 

 beneath their bodies, that it is very difficult 

 to force the animal from its position without 

 breaking the shell. 



PIIYLLIUM. A genus of insects belong- 

 popularly 

 known as Wai king -leaves ; some of which 



. 



ing to the family Phusmidce, and pop 

 known as Wai king -leaves ; some of 

 have wing-covers so closely resembling the 

 leaves of plants, that the insects are easily 

 mistaken for the vegetable productions 

 around them. They are for the most part 

 natives of the East Indies, Australia, and 

 South America. G. K. Gray Esq., of the 

 British Museum, in a communication to 

 I 'The Zoologist,' observes that "in the time 

 of Linnaeus only one species was known as 

 the Mantis siccifolium, which is figured by 

 Rosel. And it was the general opinion of 

 authors long after that great man's time, 

 that there existed but one species of these 

 remarkable insects, until Stoll gave many 

 figures of them, one of which he considered 

 to differ in some points, and gave to it the 

 name of Phasma chloropJty Ilium. The ge- 

 neral opinion having been thus broken in 



(PHYLI.IDM SIC 



ICM.) 



upon, other syecies have since been added 

 [five of them are described in the notice to 

 which we refer]. * * * These extraordina- 

 rily formed insects were, at one time, sup- 

 posed to partake both of insect and vegetable 

 life ; and not only has the perfect insect 

 such similarity to portions of vegetables, but 



even their eggs might at first sight be mis- 

 taken for the deeply ribbed fruits of various 

 umbelliferous plants." The species Phytlium 

 bilohntiim is thus described by Mr. Gray : 

 Abdomen narrow at the base, enlarging on 

 each side to the middle of the third segment, 

 and then gradually decreasing to the end of 

 the fifth ; the outer margins of the sixth and 

 seventh are lobed, with the remaining seg- 

 ments suddenly lessened to the tip. Femora 

 of the fore legs dilated ; the inner dilation 

 has the margin inwardly entire and out- 

 wardly much dentated, the outer dilation 

 oval and entire. Length of body two inches 

 nine lines. Inhabits the Philippine is- 

 lands. 



PHYLLOSOMA, or GLASS CRAB. A 

 striking genus of Crustacea, belonging to 

 the order Stomapoda. Our figure will illus- 

 trate, better than any description we mi_'ht 

 give, the form and general character of this 

 genus. There are many species, found for 



OI,ASS-3RAB. (PHYLLOSOMA STYT.rOORNIS.) 



the most pnrt in the tropical parts of the 

 Atlantic and Indian oceans : they are highly 

 transparent. Captain Grey, who had many 

 opportunities of observing them, in speak- 

 ing of one, says, " When it was taken out of 

 the water, it stood upright on its legs, and 

 crawled a little like a large beetle, but soon 

 died. In the water it swam with the legs, 

 the large joint of which appeared to be 

 feathered. It was not thicker than the thin- 

 nest wafer ; the back was marked with 

 curved lines ; and it shrank instantly when 

 touched. The species have a horny feel to 

 the touch, are destitute of smell, and look 

 like a transparent scale when they lie in 

 your hand." 



PHYSA. A genus of fresh- water Mollusca 

 occupying a small oval or oblong, smooth, 

 thin shell, generally sinistral or reversed ; 

 and no operculum. The animal has two 

 long tentacula, with e3'es at the base : foot 

 long ; mantle large, so as to cover part of the 

 shell, and very transparent. These ani- 

 mals are most frequently found on the under 

 side of the leaves of aquatic plants : they 

 have a very singular way of adhering to the 

 surface of the water with the shell down- 

 wards, and crawl in that direction with as 



,uch apparent ease as on a solid surface, 

 and they will occasionally let themselves 

 down gradually by a thread. 



PHYSALIA. A genus of Acalepha, re- 

 markable for its size, the brilliancy of its 

 hues, and the severe burning pain produced 



