209 



ICTINIA. 



IGUANID^E. 



210 





The author of the 'Analytical Notice of Books' ('Zool, Journ.,' vol. 

 ii.) says, when reviewing the 'Histoire Naturelle des Mammiferes,' 

 Nos. xli.-l., that between the Viverrine Family and that which is com- 

 posed of the Racoons and Bears there had existed a considerable gap, 

 which is now in a great measure filled up by the newly discovered 

 forms, the Benturong and the Panda. The external appearance, he 

 remarks, of the let ides corresponds in some degree with both that of 

 the civets and racoons, having the plantigrade motion of the latter 

 and the slender snout of the former. It is indeed completely planti- 

 grade, and has on each foot five toes armed with strong compressed 

 claws, apparently adapted for climbing. " Its tail, the thickness of 

 which at its commencement is almost monstrous, is prehensile beneath, 

 without being terminated by a naked skin, like that of Aides, but 

 resembling entirely the tail of the Sajous. The eye, like that of the 

 domestic cat, has the pupil vertically elongated ; the habits of the 

 Ictidti are consequently nocturnal. The ears are small and rounded ; 

 and the nostrils are surrounded by a muzzle, which is divided into two 

 portions by a deep sulcus. The hairs are long and thick, and a 

 peculiar character is given to the physiognomy by the moustaches, 

 which are very voluminous on the lips, the eyes, and the cheeks, and 

 by the pencil of long and numerous hairs which terminates the ears. 

 The cry is intermediate between those of a cat and a dog." The 

 species are found in India. 



/. albifrom. Fur gay ; hairs long, silky, black at the base, and 

 white in their extreme third, shorter on the head and limbs ; sides of 

 the snout, forehead, pencils of the ears (which are edged with white), 

 black ; upper part of the snout and forehead white ; iris yellow ; 

 belly gray, with shorter hairs than those on the upper parts of the 

 body. Size, that of a very large domestic cat. In another specimen 

 the sides of the snout, and the tail, its extremity excepted, were 

 gray. It inhabits Bootan, Nepaul (Kftchar : though they occasionally 

 occur in the central region of Nepaul. Hodgson). 



Sir Thomas Stamford Raffles describes the gait of this Benturong 

 as low and crouching, the body being long and heavy, and the legs 

 short. The tail, thick at its insertion, gradually tapers to the extremity, 

 where it curls upwards. In climbing trees the animal is assisted by 

 this tail, which ia strong. One that was kept alive many years by 

 Major Farquhar partook both of animal and vegetable food. Slow in 

 motion, and timid in disposition, the animal sleeps much during the 

 day : the night is the season of its comparative activity. Two other 

 species have been described. 



ICTINIA. [FALCOXID.E.] 



IDALIA. [NUDIBRAUCUIATA.] 



IDE, a Fish. [LEtjcisccs.] 



IDIA, Lamouroux's name fora genus of recent Polyparia, allied to 

 Sertularia (Linn.). 



IDMO'NEA, a genus of Animals belonging to the order Polyzoa, 

 described by Lamouroux as closing the group Millcporida. It is 

 ramose, the branches triquetral in section, celluliferous on two faces, 

 cells prominent in transverse rows. One species, the /. atlantica, 

 inhabits the British seas. Several have been found fossil in the Oolite 

 ami 0,'nlcaire Grossier. [PoLTZo.v.] 



IDOCRASE, a Mineral, also called Ventrian, Pyramidal Garnet, 

 &c. This mineral occurs crystallised and massive ; the crystals are 

 either attached or imbedded. Primary form a square prism. Cleavage 

 parallel to the primary planes, distinct, and less so parallel to tho 

 diagonals of the prism. Fracture uneven, slightly conchoidal, or 

 rather undulated. Hardness 6'5. Scratches glass readily, and even 

 quartz. Colour various shades of brown, black, gray, blue, green, 

 and yellow. Streak white. Lustre vitreo-resinous, translucent, and 

 transparent. Refraction double. Specific gravity 3'08 to 3'4. By 

 the blowpipe it is fusible with ebullition into a yellowish transparent 

 globule, and with borax gives a glass tinged green with oxide of iron. 



The massive varieties are amorphous ; the structure is fibrous, 

 granular, or compact. 



Idocrase is met with both in primitive and volcanic countries. It 

 occurs in the masses ejected from Vesuvius : the crystals are some- 

 times of large dimensions. 



It was found originally in the neighbourhood of Vesuvius, and since 

 in many other parts of the world. Different varieties have been 

 called by different names : thus, Cyprine is cupreous or blue Idocrase ; 

 l,tili:iiie, greenish-yellow ; Egeran, found near Eger, in Bohemia, is of 

 a liver-brown colour; Xanlhite, found at Ainsty, New York. The 

 following are analyses by Klaproth and De Kobell : 



Klaproth. Do Kobell. 



Silica .... 35-50 42'00 36 



Alumina . . . 33-00 16-25 22 



Lime .... 22'25 34-00 36 



Oxide of Iron . . 7'50 5'SO 5 



Oxide of Manganese . 0'25 Trace. 



98-50 97-75 98 



Veiuvltu. Siberia. Mua. 

 IDOTEA. [IsoPODA.1 



ID1UALIN, a Mineral Resin of a grayish or brownish-black colour, 

 with a grayish lustre, occurring in the Cinnabar mines of Idria. 



IDYA, Oken's name for those Beroes which are formed after the 

 manner of Btrut otata. [ 

 AT. BUT. BIT. VOL. in. 



IDYIA (Rafinesque), a genus of Crustacea to which Desmarest 

 alludes, among other such genera, as knowing nothing of them beyond 

 their names. 



IERAX. [FALCONID.E.] 



IEREA, the generic name of a fossil Polypifer from the blue clays 

 of the Vaches Noires (Calvados), described by Lamouroux, who is 

 doubtful of its affinities, but ranks it among his Polyparia actinaria, 

 Bronn places it among the Siphonice. 



IGNATIA, a genus of Plants belonging to the natural order 



Lorjaniacea. One of the species of this genus, /. amara, yields the 



j St. Ignatius's Beans of India, where, under the name of Papeeta, they 



I are said to be a remedy for cholera. No proof has been afforded of 



their efficacy in this disease, and Dr. Limlley (' Vegetable Kingdom ') 



says that convulsions and giddiness are known to follow their 



exhibition when given in an over-dose. 



IGUANA. 



IGUA'NID^E, an extensive family of Saurians, of which the genus 

 Iguana may be considered the type. Messrs. Dume'ril and Bibron, in 

 their ' Erpe'tologie ' (1837), treat of these reptiles under the name of 

 Le'zards Iguaniens, ou Sauriens Eunotes. In 'the Catalogue' of tho 

 Specimens of Lizards in the British Museum,' the Jyuanidce with the 

 Agamidce [DRACONINA] constitute the tribe Strobilosaura. 



Before giving the genera and species as arranged by Dr. J. E. Gray, 

 we give a sketch of the organisation of the Iguanidce. 



The skull is always articulated by a single coudyle situated below 

 the great occipital foramen which opens a passage for the nervous 

 chord. The configuration of the head presents great differences, 

 dependent on the conformation of the bones of the cranium, the face, 

 or jaws. 



The number of cervical vertebrae is most frequently sir, and this 

 region is generally short, but it is strong. There are often articulated 

 trachelian apophyses, which are in reality the rudiments of ribs. Tho 

 dorsal vertebrae, meaning by that term the vertebra; which carry the 

 ribs, vary much in number in the different genera. The first lumbar 

 vertebne are like the dorsal, except that they are without the articular 

 facets which characterise the latter. Generally there are but two 

 pelvic vertebne, which carry the ileum or pelvis. The ribs are in 

 general slender, weak, rounded, and of the same form, though they 

 vary in their curvature, according as the trunk is cylindrical, depressed 

 or compressed in the thoracic region. The first or anterior ribs aro 

 joined to the lateral parts of the sternum, or to a series of small bones 

 which occupy tho lower part of the breast ; or they are united to 

 each other on the mesial region nearly in the samo manner as in 

 the chameleons, for this disposition occurs in Polychrus and Anolii. 

 In the Dragons the posterior ribs are free and prolonged in the 

 thickness of the skin of the sides, in order to sustain the sort of 

 parachute extended on the lateral parts of the body between the 

 anterior and posterior limbs. All the species of the family have two 

 pairs of limbs always apparent, and terminated by toes, the number 

 of which varies but little. Their conformation and respective length 

 have been used as generic characteristics principally in the case of 

 Anolii, and some others which have offered some particularities, such 

 as Sitana. The presence of a shoulder formed of two bones, and that 

 of a pelvis, separates these Saurians from the Serpents. 



The general form of the body and the disposition of the skeleton 

 scarcely vary, except in the proportions of the different regions of the 

 spinal column, especially in that of the tail and in the configuration 

 of the vertebrae, the spinous and transverse processes of which corres- 

 pond to the external state of compression or depression. In the 

 greater number of species, as in those of Lophyrus, Basiliscua, 

 Polychrut, and Iguana, the region of tha back presents a well-defined 

 projection, sustained by the series of spiuous apophyses which often 

 form that crest which has caused Messrs. Dume'ril and Bibron to name 

 the family Eunota. This disposition is most manifest in Basiliicui 

 and Agama ; whilst in Stellio and Uromastix the dorsal spines project 

 but little. The bodies of the vertebra) which constitute the tail are 

 much shorter in those species in which that part is not long, Phryno- 

 cephalus for instance, than in those which have it excessively 

 prolonged. In these last, take Iguana and Anolis for example, there 

 is another peculiarity, namely, that the bodies or central and cylin- 

 drical parts of the caudal vertebra), which are large and dilated at 

 their extremities for articulation, have, at the same time, the mesial 

 portion more slender and fragile, so that it is in this portion that 

 fracture often takes place, which is followed by a reproduction anil 

 consequent deformity which the tail often in that case presents. 

 M. Kousseau (pore) found in the skeletons of those Saurians which 

 had undergone mutilation of the tail a long cartilaginous cone in lieu 

 of distinct vertebras ; and Carus has remarked, that the spinal chord is 

 not renewed in this cartilaginous stem, which is produced in lieu of 

 the caudal vertebrae. 



With regard to the senses, sight and hearing appear to be very 

 well developed in this family ; and taste seems to be present in a very 

 fair degree, but not smell ; touch moderate. The eyes of all the 

 Iguaninns are furnished with moveable lids ; the orbit in which they 

 are placed varies in its extent and in conformity with tho limits 

 which result from the bones of the face and cranium. The greater 

 part have a superciliary arch, which is sometimes tuberculous and 

 very projecting, as in Oj'hryoesaa and Hypsibatta, Messrs. Dum^ril and 



