ipopttlar SDirtiaiutrn of &m'inatctt Mature. 725 



the erected tooth struck into it, and with 

 the velocity of thought. It is found by ex- 

 periment that the effect of subsequent wounds 

 is greatly diminished either by the diminu- 

 tion of the quantity of venom, or by some 

 deterioration of its strength ; so that if a 

 venomous Serpent be mude repeatedly to 

 inflict wounds, without allowing sufficiently 

 long intervals for it to recover its powers, 

 each successive bite becomes lest and less 

 effective." 



The Viper, like many other of the poison- 

 ous groups of Serpents, is ovo- viviparous. 

 If a female Viper about to bring forth her 

 young be killed, and the young ones set at 

 liberty by opening the abdomen, they will 

 immediately crawl about, and on being ir- 

 ritated will throw themselves into an atti- 

 tude of defence. The number of young 

 produced at each birth varies from about 

 twelve to twenty. During the cold months 

 of the year the Viper, like the other reptilia, 

 finds a secure retreat in which to hibernate. 

 Shrews, field-mice, and other small animals 

 are the Viper's food. There are two or three 

 varieties, aa the Ued Viper, the Black Viper, 

 &c. 



VIRGULARIA. A genus of Coralliferous 

 Polypi, closely allied to the genus Pennatula, 

 but having the laminae between which the 

 polypi are situated much shorter. Like that 



TIRODLARIA UIRABJMP* 



genus, one extremity of it is always without 

 polypi, and somewhat resembles the barrel 

 of a feather. It is believed to be phospho- 

 rescent, like many of the other allied genera. 

 Our figure shows, better than a description, 

 the form of this singularly beautiful genus. 



VITRINA. A genus of small land shells, 

 ovate, thin, glossy, and fragile ; spire short, 

 the last whorl large ; aperture oval. The 

 body of the animal is long, with four ten- 

 tacula, two of which have eyes at the summit. 

 The species are all recent, and found among 

 moss and grass in damp situations. They 

 greatly resemble young specimens of the 

 genus Helix, from which they are distin- 

 guished by their never being umbilicated 

 or perforated. 



VIVERRA: VIVERRID^E. A genus 

 and family of carnivorous quadrupeds, 

 which in the Linnoean arrangement included 

 (besides the true Civets, to which the genus 



Ftrerra is now restricted) various animals 

 differing remarkably in form, in structure, 

 and in habits ; as ichneumons, coatiinondis, 

 genets, weasels, &c. The true Civets, as Mr. 

 Bennett, in his ' Tower Menagerie,' observes, 

 yield in the extent of their carnivorous pro- 

 pensities to the cats alone, whom they ap- 

 proach very closely in many points of their 

 zoological character, as well as in their pre- 

 datory, sanguinary, and nocturnal habits. In 

 addition to the six incisors and two canines 

 which are common to the whole of the true 

 Carnivora, they ha\e on each side and in 

 each jaw six molars, one of which is pecu- 

 liarly adapted for lacerating flesh, while the 

 rest are more or less of the ordinary form. 

 Their tongues are furnished with the same 

 elevated and pointed papillae which give so 

 remarkable an asperity to those of the cats, 

 and their claws are half retractile. The 

 toes are five in number on each of their feet, 

 and their extremities alone are applied to 

 the ground in walking ; the animals are 

 consequently completely digitigrade. But 

 the most distinctive character of the group 

 consists in an opening near the tail, leading 

 into a double cavity of considerable size, fur- 

 nished with glands and follicles for the se- 

 cretion of the peculiar odoriferous substance 

 so well known as the produce of the Civet, 

 and from which the animal derives its name. 

 [See CIVKT.] 



VIZCACHA. [See BIZCACHA.] 



VOLUTA : VOLUTIDJ3. A genus and 

 family of testaceous gasteropodous Mollusca, 

 principally found in tropical seas, and whose 

 shells are prized above most others for their 

 beauty and rarity. The animals inhabiting 

 them have the head distinct, and two short 

 triangular tentacula, with eyes at the base, 

 and a long thick proboscis or trunk ; foot 

 very large. The foiutidce comprise nume- 

 rous species, both recent and fossil, and may 

 be regarded as one of the most interesting 

 and beautiful families of the spiral Testacca, 

 whether in regard to the elegance of the 

 shells themselves, or as exhibiting a principle 

 of variation in their structure hardly to be 

 excelled. They are generally smooth, shin- 

 ing, and the colours bright and varied ; they 

 differ exceedingly in form and size, some 

 being globular, others oval, some turreted, 

 and others with only a very small spire ; but 

 though they vary in the figure of the shell 

 and of the aperture, they are recognized by 

 the emorgination without a canal which ter- 

 minates it, and by the oblique plaits of the 

 columella. Some of them have spines at 

 the upper part of each whorl, which form a 

 kind of thorny crown ; many are curiously 

 marked with lines and spots, so as to form 

 some resemblance to a line of printed music; 

 and one very scarce species is marked with 

 five or six transverse milk-white bauds upon 

 a dark ground, and spotted with reddish 

 brown, forming a beautiful contrast of co- 

 lours. Many of them attain a very la 

 size ; but the fossil species are 

 smaller than the recent. 



VOLVARIA. A genus of Univalve 

 Mollusca, found on the coasts of Africa and 



SQ 3 



