lOtrttounri? of m'matetr Mature. 55 1 



tacula : foot small. The shell is oblong ; 

 spire small ; mouth terminated by a rather 

 long canal ; right lip dilated into several 

 claws, and having a sinus near the canal ; 



. (PTEROOERAS 300RPIO.) 



operculum horny. The appearance these 

 shells present at various periods is strikingly 

 different. When the animal is young the 

 shell has no claws ; but they gradually make 

 their appearance, at first in the form of short 

 and open canals, which by degrees assume 

 the length and curve of the adult and com- 

 pleted shell, and ultimately are closed up 

 with shelly matter and become solidified. 

 The number of claws varies in different spe- 

 cies ; in some they are straight and smooth ; 

 in others they are numerous, but small ; 

 whilst many have these appendages very 

 much curved. Some of them exhibit the 

 most beautiful colours on their internal 

 surface. Our cut represents Pterocertis scor- 

 pio: the DEVIL'S CLAW. 



PTERODACTYLUS. The name given 

 to a genus of extinct Reptiles, which are 

 supposed from their structure to have occu- 

 pied that share in the economy of nature 

 which is at present assigned to the Bats and 

 Insectivorous Birds. From the size and 

 form of the posterior extremities, the Ptero- 

 dactylus seems to have been able to walk 

 and perch upon them, after the manner of 

 birds ; and by using both its anterior and 

 posterior limbs, it could probably walk and 

 climb on rocks and cliffs, like Bats and 

 Lizards. They have been found in the lias 

 and oolite formations, greatly varying in 

 size, and generally mingled with the re- 

 mains of Dragon-flies, Beetles, and other 

 insects. 



It appears that the opinions of philo- 

 sophers with regard to the true nature of 

 this extinct animal were various and con- 

 tradictory, until the reasonings of the great 

 French Naturalist solved this zoological 

 puzzle. " Behold," says Cuvier, " after 

 having built, as it were, the animal before 

 our eyes, an animal which, in its osteology, 

 from its teeth to the end of its claws, offers 

 all the characters of the Saurians ; nor can 

 we doubt that those characters existed in 

 its integuments and soft parts in its scales, 

 its circulation, its general organs. But it 

 was at the same time an animal provided 

 with the means of flight, which, when sta- 

 tionary, could not have made much use of 

 its anterior extremities, even if it did not 

 keep them always folded, as birds keep their 

 wings, which nevertheless might use its 

 small anterior fingers to suspend itself from 

 the branches of trees, but when at rent must 



have been ordinarily on its hind feet, like 

 the birds again ; and, also like them, must 

 have carried its neck sub-erect and curved 

 backwards, so that its enormous head should 

 not interrupt its equilibrium." Dr. Buck- 

 land, whose attention has been especially 

 directed to the examination of extinct ani- 

 mals, dwells at considerable length on the 

 presumed habits and character of the Ptero- 

 dactylus ; and exclaims, "Thus, like Milton's 

 fiend, all-qualified for all services and all 

 elements, the creature was a fit companion 

 for the kindred reptiles that swarmed in the 

 seas or crawled on the shores of a turbulent 

 planet. With flocks of such-like creatures 

 flying in the air, and shoals of no less mon- 

 strous Ichthyosauri and Plesiosauri swarm- 

 ing in the ocean, and gigantic crocodiles 

 and tortoises crawling on the shores of the 

 primeval lakes and rivers, air, sea, and land 

 must have been strangely tenanted in these 

 early periods of our infant world." 



PTEROGLOSSUS. [See ARACAEI.] 

 PTEROMYS, or FLYING SQUIRREL. 



[See SQUIHKKL.] 



PTERONARCYS. A genus of Neurop- 

 ! tera first described by Mr. Newman. It is 

 i allied to PEULA ; the finest species, Pteronar- 

 \ cys reyalis, is a native of Canada and other 



more northern parts of North America. 



Mr. Barnston, a gentleman belonging to the 



i Hudson's Bay Company's service, and who 

 has paid much attention to Natural History, 

 especially to that part of it which regards 

 insects, mentions in his notes that the spe- 

 cies of this genus shun light, concealing 

 j themselves during the day under stones in 

 , damp places, and appear on the wing at 

 nightfall, when the air is charged with 

 moisture. But the most remarkable fact 

 , connected with this insect is the discovery 

 by Mr. Newport, of persistent branchiaa in 

 the perfect state ; in the larva, and, it is 

 believed, in the pupa state, the insect lives 

 constantly in the water ; and in ordinary 

 states of the atmosphere, such branchite 

 i would be no longer necessary, but in this 

 ! ease their continuance would seem a peculiar 

 provision of Nature suited to the damp at- 

 i mosphere in which it lives, Mr. Newport 

 ! observing, that " the function of branchiae, 

 or aquatic organs, is equally well performed 

 in,the open air as in water, so long as the air 

 is charged with a sufficiency of fluid to pre- 

 serve these organs in a healthy state." We 

 eagerly look for an elaborate memoir on this 

 anomalous occurrence from the pen of our 

 most talented comparative anatomist in the 

 field of articulated animals. 



i PTEROPODA. The name of a class of 

 Molluscous animals, particularly distin- 

 guished by the possession of a pair of fin- 

 \ like organs, or wings, consisting of a natatory 

 ! expansion of the mantle on each side of the 

 I neck, by the aid of which they are rapidly 

 , propelled through the water. Some of them 

 have a shelly covering ; others are unpro- 

 : yided with such a protection ; but wherever 

 i it exists, it seldom covers more than the 

 posterior half of the body, and is extremely 

 j light and delicate. The head of these ani- 



