SvsTEiMATic Arrangement. - 



-EEPTlLES.- 



-SvsTEMATic Arrangement. 



Ihem to aiUieve fiimly to tlie surface of tlie objects upon 

 wliioli tliey move, than to serve as organs of touch. 



Ueptiles eat and drink very little, and they are 

 capable of undergoing long fasts. The greater number 

 of them are carnivorous, very few subsisting entirely 

 upon vegetable substances. Amongst tlie vegetable 

 feeders are the land tortoises and some of the marine 

 species. In the case of almost all the rest, it is living 

 prey only that the}' eat, and the animals upon which 

 they feed are generally swallowed entire. The struc- 

 ture, form, and position of the teeth in the carnivorous 

 reptiles vary niucli, and form good characters for 

 dividing them into generic groups. Besides the teeth 

 Mliicli are planted in the jaw-s, thei-e are others which 

 are inserted upon the bones of the palate. In the 

 herbivorous tortoises, and all the Chelonians, teeth, 

 however, are entirely wanting. In these animals the 

 jaws have a considerable resemblance to those of birds, 

 being sharp-edged and horny. The lower jaw shuts 

 within the upper, and the portions of food are cut or 

 snapped off", as it were, on the principle of shears. 

 Ltigestion is very slow, and indeed is carried on only 

 in proportion to the degree of temperature of the sur- 

 rounding atmosphere. " Many Serpents," says Mr. 

 I'ell, " are more than a fortnight after taking their 

 food before the undigested remains are voided, during 

 which period they usmilly fast. If the temperature 

 in which they are placed be very low, it is greatly 

 letarded, and during hibernation it ceases altogether ; 

 for I have knowii a tortoise, whicli had fed largely 

 upon grass immediately before it became torpid, retain 

 the grass unchanged in the stomach during the whole 

 of the winter; so that, on opening the body after its 

 death, whicli took place immediately on its awaking 

 in the spring, and before it had an}' access to food, tlie 

 stomach was found filled with a large quantity of grass 

 wliolly undigested." 



Reptiles are for the most part oviparous, that is, 

 they lay eggs which are hatched after expulsion. The 

 mother buries them in the sand, or deposits them in 

 some place of concealment, exposed to the rays of the 

 sun; and in due time, without any further assistance 

 from the parent, the young are hatched. In a few 

 instances, however, the female retains the eggs within 

 her body, till the young are ready to burst the shell, 

 which are then excluded perfectly formed. Such is 

 the case with the common lizard and viper of this 

 country, and some other serpents, the blind-worm, &c. 



The following is the arrangement adopted in the 

 British Museum, where there is an extensive collection 

 of reptiles. The method is that of Dr. Gray: — 



Class.— UEPTILES {Ileptilia), from the Latin word repto, 

 to creep, or crawl. 



Animal furnisliej with a distinct liony skeleton. The skin 

 clotlied Willi horny imbedded jdates or imbricated scales, wliicli 

 are covered with a thin, and often deciduous epidermis. Ttiey 

 respire by cellular lungs. The heart is trilocular, that is, it 

 lias a single ventricle divided into two or more cells, giving 

 origin to two arteries, and receiving the cold red blood by two 

 veins, from two auricles. Oviparous, but the eg$ somelinies 

 hatched in the body of the mother, often covered with a thick, 

 more or less calcareous shell. The young like the parent, and 

 not undergoing any tran^fornnition. 



Reptiles are divided into two large sections, the iicaly and 

 ShieUkd, according to the structure of the scales or plates 

 with which the skin is covered, and the formation of the skull. 



Section I. — Scai.v Ueptilks {SipiaimUa), from the Latin 

 word sijuamu^ a scale. 



Body covered with overlapping scales. Skull fu-nn-d of 

 separate bones; the ear-bone external, and only articulated to 

 the rest. Tongue free, elongate, nicked at the tip, often 

 extensile. 



This section is composed of two orders, containing all the 

 species denominated •'^anrians or Lizards, and UiihltliutiSy Ser- 

 pents or Snakes. 



(Jnkr 1. — LlXAKOs [Sniniu]^ from the Greek word aanros 

 {trxu^o;)^ a Hzard. 



Month not dilatable, jaws toothed, lower jaw-bi;uie3 

 united by a bony suture in front ; eyes generally w-ith 

 distinct eyelids ; limbs four, distinct, rarely in such a 

 rudimentary state as to be hiilden under the skin ; body 

 elongate, rounded, covered with imbricated or granular 

 scales ; tail elongate, tapering, occasionally prehensile, 

 generally covered with whirls of scales. 



This order is divided into two sub orders, from the 

 structure and form of the tongue. 



'S'lih order 1.- — Slender-tonguep Lizards {Lepto- 

 (jlossw), from the two Greek words. Idpfus'^iTr^;), 

 smooth, and f/lossit (yf-ua-ffx)^ a tongue. 



Tongue fiat, elongate, bifid. To tiiis sub-order 

 belong the Monitots, the Tegitexiiis, the true 

 fur:ar(ls, the *Sci/fi.9, ttc. 



SlllMinUrl. — TlIlCK-TONGUEDLlZAUI)B(i'.;c/i;/;//os«(B), 



from the two Greek words, pnckiis (tdcxs/.-j, thick, 

 and gtossa {yK&itnra\ tongue. 



Tongue thick, convex, attached to the gullet at 

 the base. To this sub-order belong the Qeckua. 

 the Igjiaiuts, the Dragons, the Agamas, and ilie 

 dtiimcieotis. 



Order '2. — Serpents [Ophidia], from the two Greek words, 

 ophis (6p;\ a serpent, and eidos (J'^of), form or 

 shape. 



Jlouth very dilatable ; bones of the lower jaw sejm- 

 rate from each other, only united by ligaments ; facial 

 bones moveable ; limbs none, or only in the form ^^i 

 short spurs on the sides of the vent; tongue very ioiig, 

 retractile into a sheath at its base, apex forked, very 

 hnig, slender, tapering ; one lung very large, the other 

 small or rudimentary. 



This order is divided into two sub-orders, the Viperii.e 

 .Serpents [Viperiiia], and the Colubrine Serpents [Culu- 

 briiut) . 



Sith'Order 1. — Viperine Serpents {Vqierum), from 



the Latin word vipera, a viper. 



Jaws weak, upper jaw toothless, with large 

 fangs in front, lower toothed. Head large behind, 

 crown flat, generally covered with scales, rarely 

 with shields. Hinder limbs not developed. Eyes 

 lateral; nostrils lateral, apical, open. Tliis sub- 

 order contains the eminently poisonous serpents, 

 such as the Rattlesnakes and the Vipers. 



Siih-order 2. — Colubrine Serpents (Cduhrinu), 

 from the Latin word coluher, a snake. 



Jaws strong, both toothed, sometimes with some 

 fangs in front, or grooved teeth behind. Head 

 moderate, or indistinct ; crown often covered with 

 regular shields. This sub-order contains the Waler- 

 smih'3, some of which are poisonous, the lioas, and 

 numerous htirmless serfients, such as the True Ser- 

 petits. the H'oo(/ iScrpents, the Tree Serpents, &c. ; 

 and tlie Naja group, which contains the Ct-hra de 

 Capello, and oilier venomous species. 



Section II. — SniELUEn Reptii.es (Catapliracta), fn'in the 

 Greek word bitajihrasso (««r«;{««-»-<»), to cover or protect. 

 Body covered with square imbeilded plates, generally form- 

 ing ad'orsal and central shield; bones of^ the skull agglutinated 

 together, hard, with the car-bone sunk into its substance ; jawa 

 united into a solid mass; mouth not dilatable ; tongue short, 

 affixed to the mouth, scarcely exsertibic ; the egg covered wiih 

 a hard shell. 



This section consists of three orders, containing the Tortoises 

 or Chelonians. the Crocoililcs or Emytlosauriana, and the Am- 

 phisbaenians, A nqJi isbienia. 



