'.^M'^^^i^ -IV' AUG S 1910 ►^ ^UG S 1910 REPTllilA WkITTEN Foil THE STANDARD NATURAL HISTORY, BY HERMON CAREY BUMPUS, Assistant in riiii Zoological Laboratory of Crown University. BOSTON : S. E. CASSINO AMD COMPANY. 1885. REPTILES. 345 Class Yni. — REPTILIA. Reptik's arc cold-blooded animals which breathe by means of lungs, and gen- erally have the ventricles of the heart but incompletely separated from each other. The body is jirotected, externally, by scales or armor phstes, and the embryos are pro- vided with an amnion and an allantois. A general structure is jiresented somewhat higher than that of batraeliians, and lower than, th<>u<;h strongly resembling, that of birds. The general form of the body is that of the jirevious class. The trunk usually plays the chief part in locomotion, while the lindis are either entirely absent, as in Oj>hitlia, or, among the lower forms, are present oidy as aids in the ser])entine move- ment. To this end the vertebral column is strong and rigid, terininating posteriorly in an elongated tail, and presenting but feebly those regions so distinct in the birds and mammals. All reptiles, however, are not of this low type; tlie tortoises, several lizards, and many fossil forms have the limbs well developed and the vertebral column more or less differentiated. Protection from injury with most of the smaller reptiles lies chiefly in resem- blance, color, and in the sliielded areas of the skin, the outgrowths of wdiich may be from either the dermis proper, as'the scale-like ossifications of many lizards, or from the epidermis, as the corneous plates of the crocodiles and turtles. Many serpents and the remark.alilc lizard JIdoderma are provided with poison apparatus, which renders a conflict with them of the most dangerous nature. The larger reptiles trust alone to sheer force for protection. The skeleton is seldom otherwise tlian strong and bony, and though many fossil forms, as well as the geckos and Hatteria, have bi-concave vertebral centra, as a rule the bodies of the vertebrae are concave anteriorly only. Ribs are quite characteris- tic, — in the ser]ients being the chief organs of locomotion, and in a few lizards forming the support of the so-called wings. They are often united to a sternum by means of sterno-costal pieces, and in the crocodiles a cartilaginous plate extends from stt'rnum to pelvis, bearing lateral processes which serve the function of ribs proper. The skull is composed of well-ossilied bones, the embryoiuc condition presented by many batra- chians being supplanted, and is connected with the axial skeleton by means of a single condyle. The specialized cranial structnre presented by the Ophidians is of particular interest, and will be spoken of in connection with that grouj). The limbs and their respective girdles, though completely absent in most snakes, are generally present and are often highly si)ecialized. The nervous system is a decided advance on that presented by the previous class. The hemispheres are large, and show an inclination to overlap the jiortions of the brain i^osterior to them. The cerebellum exhibits a regular advancement in develop- ment, coincident with that presented by the respective rejiresentatives of the class from Ophidia to Crocodilia, where avian peculiarities are anticipated. As to the organs of s])ecial sense : In the serpents and a few lower lizards, eye- lids are not present. When thus unprotected, the cornea is covered by a crystal-like scale which holds a tliin layer of lachrymal fluid. Hearing is of varying delicacy. A 346 LOWER VERTEBRATES. tympanic membrane, with its cavity and eustachian tube, is present in all the forms ex- cept the serpents and some footless lizards. The organs of smell are usually well devel- oped, and in some aquatic forms the external nares are provided with valves. The sense of taste is often more or less defective, and its seat is probably not in the tongue alone, but also in sjiecial areas of the mucous membrane of the buccal cavity as well. The jaws of all existing reptiles, excepting the turtles, are provided with small, sharp, often recurved, prehensile teeth, which never serve thd office of mastication, but are used to grasp and retain the prey. Teeth may also be on the palatine and ptery- goid bones. (The specialized maxillary teeth of the poisonous serpents will be men- tioned in connection with that group.) Salivary glands are present in both serpents and lizards, and sub-lingual glands are characteristic of the turtles. The oesophagus is long, capable of great dilatation, and its walls are usually longitudinally folded, though in turtles they are provided with papillre ; it leads into a stomach, transversely placed in Chelonia, though longitudinal in other forms. The intestine, in all save the herbivorous turtles, is short and but little coiled, and ends in the clo.aca, which opens externally by a round opening, or in serpents and lizards by a transverse slit. Respiration is always performed by means of lungs, and these, except in the serpents and the apodal lizards, are of equal size and of the ordinary structure. Air enters through the slit- like glottis and reaches the lungs by passing down an elongated trachea and bronchial tubes. The ribs play a most important part in breath- ing; though tlie rigidity of the cara- pax and plastron of the turtles compels the membei-s of this group to force the air into the lungs by swallowing it. The organs of circulation are of particular interest, as they present the several stages of development from that of the batrachians to birds. The right auricle is the larger and receives the systemic, while the left receives the pulmonary veins. The ventricles are only partially separated from each other in the lower forms, and mix, to a greater or less extent, the venous with the arterial blood. Right and left aortic arches are present. The crocodiles, however, have the ventricles separated by a parti- tion, and a structure resembling that of birds is obtained. The right aortic arch and carotids arise from the left ventricle, while from the right ventricle arise a left aortic arch and the pulmonary arteries. The renal organs are in the hinder region of the trunk, and the turtles and lizards have the urinary bladder a])pended to the anterior wall of the cloaca, into which also open the genital ducts. The reproductive organs are more or less bird-like, the intromit- FlG. 206. — Heart of lizard from beneath ; the aerated blood indicated by dots, the uiiaerated by crosses ; a, abdominal or descending aorta ; f , carotid artery ; I, left auricle ; L, lungs ; jfa, pulmonary artery ; pv, pulmonary vein ; ?•, right auricle ; s, subclavian artery ; /, trachea ; v, ventricle ; /, //, ///, / V, remnants of branchial arches. REPTILES. 347 tent organ of the male in the kiwer forms (0])lii(lia antl Laccrtilia) is paired. Though, as a rule, reptiles are oviparous;, there are several forms which retain the eggs, until they are hatched, in an enlargement of the ovarian tube. These forms, of which many viperine snakes, as well as the horned toads and some of the ajiodal lizards, are illustrative, are said to be ovoviviparous. As to the developmental history of this braucli, that of the birds is foreshadowed. The egg is of considerable size, and often contiins a suiijily of food for the growing embryo. By a folding together of the ventral walls of the body, the embryo, though at first lying prone u|)on the egg, is finally only connected with it by a small jieduuc'le, the umbilicus, through which is drawn the nourishment of the food yolk. The amnion is a thin membrane enclosing the embryo, which floats in liquid. The allantois is an organ of embryonic life, and jierforms the office of a resi)iratory sac. It is aj)i)ended to the posterior ])ortion of the alimentary tract, and is oidy met with in those animals which are unprovided with gills, and which do not, on leaving the egg, j)ass through metamorphoses. These two organs, the amnion and allantois, first appear in the rejitiles. Having now, in a cursory way, examined the general points of structure presented bv the various members of the class, an inquiry into its relations can be profitably made ; it is here that the real value of paleontology presents itself. By considering the fossil forms, the reptiles are seen to pass imperceptibly into the birds, and the birds are found to reach over, as it were, and greet the reptiles. The dinosaurs were rejv tiles having the pelvis, hind limbs, and feet strongly resembling those of the ostrich, and some of the bones of the body were supplied with air-cavities. Many were biped, the anterior limbs being extremely small. That they were provided with teeth does not argue their non-avian affinities, for the lower birds, like ITesperoniis, were well supplied with these organs of prehension. The most remarkable avian peculiarities are presented by members of the highest order, Pterosauria. These flying reptiles had the bones of the fore limbs resembling, to no little extent, those of birds ; the neck and head were long ; the jaws were sometimes toothless, and encased in horn ; the tail was short, and the shoulder-girdle, keeled sternum, and hollow bones carried the resem- blance still further. As a result of these resemblances, together with those advanced by the anatomist and erabryologist, the birds have been united with the reptiles into a single group, the Sauropsida, the propriety of which arrangement is daily more and more evident. Although the snakes and a few lizards extend well up into the temperate regions, which is the true home of the turtles, by far the greater number are found in the torrid zone, from which the Crocodilia do not ordinarily wander. As reptiles are animals illy adapted for migration, they endure the cold of winter by passing into a tor])id sleep — hibernation, and the enormous heat of the tropical sun by a some- what similar summer sleep. Reptiles first made their geological appearance during the carboniferous age, and abounded during the mesozoic, when they were rulers of the air, land, and sea. The classification now generally adopted divides the class Reptilia into eleven orders. 348 LOWER VERTEBRATES. Order I. — OPHIDIA. The characteristics which separate the ophidians or serpents from the other orders of the Reptiles may be briefly stated as follows: An elongated body, I^rotected by scales, which cover, j^roportionally, much less 'of the integument than those of the higher reptiles, or those of the fishes, and are so attached as to allow con- siderable distention of the underlying skin. Limbs are rarely represented, and never except as a pair of ])osterior rudiments. The tongue, capable of protrusion, is of a dark red or blue-black color. A urinary bladder is not present. Though themselves small in diameter, the ophidians prey on animals of considerable size, and that these may be swallowed whole, the entire structure of the body is specially adapted. The bones of the skeleton, including those of the head, except those whose special func- tion is to protect the brain, are not anchylosed as in most other animals, but connected by ligaments only, allowing the bones considerable individual movement ; this spe- cialization is characteristic. In general form the serpents may be regularly cylin- drical, there being no external constrictions marking the divisions of the body, as head, trunk, and tail ; or the several portions may be very distinctly shown. The head is, in the majority of common snakes, of a depressed, conical shape, though in some it is flat and triangular, or rounded and fusiform. Tiie mouth is generally large and distensible ; though in forms like Tt/phlops, it is small, and capable of only limited expansion. The body — or, more properly, the trunk — is ordinarily cylindrical, though many forms have the jjovver of laterally expanding it so as to give them, when viewed from above, the appearance of more than actual size, this habit is possessed by many of the Proteroglyplis, forms like jVaJa having even the bones of the neck specialized to this end. Lateral cbmpression and vertical expansion is characteristic of many innocuous forms, especially so of the tree-snakes. The tail of ophidians, that portion of the animal behind the vent, presents as much variation in general outline as any por- tion of the body. Though generally round and tapering, in Sili/bura it is short and truncate; in many underground snakes it is rounded, stout, and blunt, performing the office of a lever ; and in the sea-snakes (Hydrophidie) it is compressed and vertically expanded. It may be terminated by a small cap-like scale, as in many common forms, by a short spine, as in some of the Opoterodonta ; by a long spine, as in Acantho- phis and Piti/ophis ; by a rattle, as in the Crotalidse, or it may be simply fusiform and scaled. In regard to the organs of special sense, the ophidians are somewhat defective. The sense of sight, from observations made by Dr. Yarrow, seems to be more or less imperfect, and though the eyes, being unprovided with lids, must be incessantly on the alei't, they are by no means the chief organs for discovering the whereabouts of the prey, the senses of smell and touch here being of chief value. Younger snakes have the eyes proportionally larger. The sense of hearing is dull, so much so that "as deaf as an adder" has become proverbial. There are no external organs of hearing, and it is probable that reptiles feel the jar produced by an approaching animal rather than that they distinctly hear it. The sense of smell is more acute, and by it the animals find their food, as well as tlieir mates ; many are known to exude a most permeating odor. The nostrils are placed at the apex of the snout, and, in those forms which are aquatic, are provided with valves. The tongue is a tactile organ, SERPENTS. 349 ami, by a special opening between the jilates of the front of the mouth, can he protnided while the jaws are closed ; in tlie HydrophidjE a special arrangement per- mits this without admitting the water. The sense of taste is probably wanting, as the reptile swallows its prey without mastication, though some forms crush it in the coils of the body. All ophidians are carnivorous. The serpents are co^•ered by an armature of scale-like folds of the skin, which are ordinarily imbricated, though in some forms they are merely juxtaposed. The armature of the lower surface of the body, in terrestrial forms, consists of a series of transversely elongated scales, known as abdominal scutes, and the head is in most cases protected by a regular arrangement of plates or shields. These shields, modified or otherwise, and their arrangement, are of great value in determining spe- cies, as they are very characteristic. The scales of the body are either smooth or ]irovided with one or more longit\idinal ridges, or carina?, and are arranged in longitu- dinal rows of equal number each side of the vertebral ridge, along which there is gen- erally a more or less peculiar series, though in Stenostoma and Herpetodryas this row is absent, making an even number of rows. In some forms, like Kaja, which distend their necks, the number of rows in that region is increased. The ventral scutes are Fig 207. — Upper, side, and lower views of bead of siialte, to sliow the plates covering it. 1, rostral ; 2, nasal ; 3, loreal ; 4, preoculars or anteorbitals ; 5, postuculars or postorbitals ; 6, temporals ; 7, internasals ; 8, prefrontals ; D frontal ; 10, superciliary or supraocular ; 11, parietals ; 13, labials ; H, infralabials ; 15, gular ; 16, mentals ; 17. sub-mentals ; 18, ventrals ; 19, dorsals. ordinarily entire in outline, though in Dcndrophidje they have a jiair of notches, and in Hydro])hidiB they are replaced by scales of the ordinary kind. As each of these .abdominal scutes is attached to a pair of ribs, their number corresponds with the number of vertebrae, and is hence of considerable diagnostic value. The scute immediately in front of the anus is often divided, as are those underlying the tail, the sub-c.audals. Of tlie plates of the head it may be said that, as they vary but little in different individuals of the same species, they are the most important factors in specific deter- mination. They are named from the parts of the head which they protect. The frontal scute overlies the frontal bones, and is generally entire; posterior to it is the ])air of parietals, while anterior are the prefrontals, or, as they are sometimes called, posterior nasals. Bordering on the parietals, frontal and prefrontals, and extending out over the eyes, are the sujiraorbitals or supraciliary plates, while posterior to the pari- etals are the generally scale-like occipitals. At the point of the snout is the rostral, and Iving between it and the prefrontals are the intern.asals. The labials line the ui>per lip, and in the pythons are deeply pitted. The lower li]) is similarly armed by the infralabials. In front, the rostral is o]iposed to the mental or chin ]>late. Around the eye are anteriorly the preorbitals, posteriorly the postorbitals, and, frequently, below the 350 LOWER VERTEBRATES. infraorbitals; behind the postorbitals are the subdivided temporals. The nostril opens through a plate, the nasal, which may be and often is divided ; between it and the preorbitals is the loreal, a sliield quite characteristic of harmless snakes. Posterior to the mental, and lying between the infralabials, are the submentals and gulars. Ordinarily the serpents have regular periods of sloughing the skin, which differ with different forms. Some little time before the change takes place, the waste skin so cleaves from the eyeballs as to render the serpent partially blind, making it unusually irritable. The skin then splits away from the margin of the mouth, and either by gliding through some narrow opening, oi- by jtassing through a ring of its own bod}', the serpent emerges, leaving its old coat turned inside out, but in perfect condition. If, as often happens in confinement, the animal lias become ill, the slough- ing is only partial, and, losing all appetite, it eventually dies. As a rule, with the exception of a hiss produced I))' forcibly exi^elling the breath, the serpents are dumb ; though Krefft maintains that some make a drumming noise, and the Indian Ptyas niucosus is said to give rise to a note like that of a tuning-fork. Garman has observed that some of the boas whine. The 25rogression of ophidians is reducible to three modes. The animal may glide, perhaps in a perfectly straight line, by use of its ventral scutes, each, on finding some resistance, forcibly pushing tlie animal forward. It may walk, by allowing each scute to act as a pair of feet, the lateral portions being alternately carried forward and pushed back ; an undulatory movement like that of myriapods would result from this mode. The third manner is by pushing, as the underground snakes do almost exclu- sively. Ordinarily ophidians combine the three methods. The sea-snakes progress by an undulatory movement, and by the sculling action of the paddle-like tail. No ser- pent can move forward on a perfectly smooth surface. It is impossible for any ophidian to jump, and it is with extreme difficulty that more than the anterior half of the body can be raised, unassisted, from the ground, though with some support, as the side of a box, the animal can stand almost verti- cally. In habits tliey are chiefly diurnal, though there are several troiiical forms which hunt during the night. Most, if not all, have some period of the year during which they become inactive. In the torrid zone this may be called jestivation, while in the colder climates it is true hibernation, the animal being apparently in deep sleep; though if kept warm and constantly irritated it will pass the winter as it does the summer, and without any ill effects. The coloration of ophidians is varied, and offers some of the most striking illus- trations of adaptation and protective resemblance. Some of the rattle-snakes, which live in more wooded sections, are, on exposure on the hot neighboring plains, changed to a much lighter shade, and the members of all families have the general coloration harmonizing well with their surroundings. The tree-snakes are always of colors resembling either the leaves or twigs among which they live. The common grass- snake, CijclojMs vernalis, offers an excellent illustration of adaptive color. In the tropics many perfectly harmless forms have adopted the coloring of the most venomous, while the Tro])ido>wtus macro2)Iitliahn%is offers perhaps the most wonderful illustration of jirotective resemblance known to the order. This inno- cent animal has not only the general form, habits, and markings of the deadly cobra, but even that animal's distensible neck and elongated ribs, — a perfect counterfeit. Whether snakes swallow their young has been much discussed. The case stands SEJiPEXTS. 351 thus : Many people maintain they have seen the animals pass into the mother's mouth in time of clanger ; some fislies, Arii, are known to jjrotect their young by re- taining them in the mouth ; a male ampliibian, Ilhinoderma dancinii, carries the eggs in a laryngeal pouch until they are well developed; young serpents could live for some time shut up in the mouth, gullet, or even stomach of their parents ; the belief is an old one and well established. On the other hand, no naturalist of good standing has ever been able to observe the young ser])ents thus seek safety ; and of the serpents found in the gullet of dissected snakes, all have been of a different species, or immature individuals of the same species as their devourers, and were undoubtodly taken as food. The skeleton of ophidians is chiefly axial, there never iK'ing any pectoral girdle, and only rarely (in Opoterodonta and a few families of Colubriformia, as the Tortrici- daB, Pythonidfe, and Boidse) a pelvic girdle with rudimentary limbs. When the hind limbs are present, they appear, externally, as two short claws or processes each side of the anus, and are probably used as clasping organs. The two rami of the lower jaw are not united in front by a bony sym- physis, but by an elastic ligament, giving them considerable lateral expansion with the ordinary vertical movement. The bones of the upper jaw are also so connected with the other bones of the face as to allow more or less individual movement. The teeth are never peiTiianent, but are capable of being renewed, like those of fishes, as soon as the old ones are worthless. They all point back- ward, and those of the palatine and pterygoid bones resemble the armature of the jaws. The vertebraj are concave in front and convex behind, and connected by free ball and socket joints, twisting being prevented by horizontal articular surfaces ; those of the body seldom exceed three hundred in number. The ribs are the chief organs of locomotion, being attached at their free ends not to a sternum but to the ventral scutes. The alimentary system is elongate and adajjted to the general form of the bodv. In the disten- silile mouth the food is subjected to the treatment of saliva, which, in its or- dinary form or as poison, is given off in considerable cpiantities, and materially aids in the process of digestion. The stomach is a simple enlargement at the end of the (Esophagus, provided with longitudinal folds, and in turn leads into a rel.atlvcly short intestine. The liver is asymmetrical, and passes from the anteriorly placed heart to the pylorus ; its reservoir, the gall bladder, is somewhat removed, and is placed, with the pancreas and spleen, in a fold of the duodenum. Though serpents drink a great deal of water, and will perish if it is not given them, they have been kept for months without nourishment of any kind whatever. The respiratory system is peculiarly specialized. The lungs are paired only in the boas, some Proterogylphs, and the Crotalida;, in other forms only one is developed, which may be specialized into an air-sac posteriorly, its fellow appearing only as a ruiliment. The trachea is long and may be jirovided with air-cells, and the larynx can be projected Fig. 208.— Skull of snake ( Tropidonoliis) ; an, angular ; ao, antorhital ; «r, articular ; */, dentary ; *'", exoccipital ; ,/*. frttntal ; p, parietal ; pl^ palatine ; /»», prernaxillary ; pr, prootic ; ;)?, pterygoid ; 7, qu.adrate ; sa, surangular ; sh, stylohyoid ; &o, supraoccipi- tal ; S7, squamosal. 352 LOWER VERTEBRATES. during the tedious process of swallowing, when, too, the tracheal air sacs and the pos- terior reservoir come into play. The ovaries and testes are paired ; the right, however, is often the larger and placed in advance of the left. The male lias a pair of introniittent organs, which are grooved, and, wlien in use, are everted, like the finger of a glove. Some species have these organs armed with sharp spines or hooks, antici]>ating the special development of some of the rodents. No urinary bladder is found in Ophidia. The eggs of ser])ents are oblong in form and covered by a leathery envelope, for the rupture of which the embryos are provided with an egg-tooth, a special develop- ment like that of the chick. The eggs, whose embryos are well advanced before deposition, are ordinarily left to care for themselves, though the pythons con- tinue to protect them, winding their body around, and, with their feeble heat, incvibat- ing them. In some forms, especially the members of the Solenoglypha and some of the Proteroglyphs, the eggs hatch in the oviduct, an occurrence which may happen in snakes ordinarily oviparous, and the young are thus born. The classification herein adopted arranges all the members of the order Ophidia in four sub-orders : Opotero- donta, with non-distensible mouth, facial bones immovably connected, teeth only in one of the jaws, and the posterior limbs as rudiments ; Colubriformia, having teeth in both jaws, no fangs, and including all the more common harmless snakes ; Protero- glypha, poisonous snakes, with large, permanently erect, grooved fangs, which are placed anteriorly in the upper jaw, and are usually immediately followed by ordinary teeth ; Solenoglypha, with the perforated fangs unaccompanied with ordinary teeth and capable of being depressed. Sub-Order I. — OPOTERODONTA. The first sub-order includes those forms which, because of their imperfect eye- sight (rendered so by the odd arrangement of the lateral cervical jilates, which so cover the eye as to render vision extremely indistinct), are popularly known as ' blind- worms.' They are provided with a narrow, non-distensible mouth, and the bones of the head are more firmly united together than those of other ophidians. The solid, hooked teeth are only in one jaw (upper or lower) and the body is terminated by a short tail. Posterior limbs are sometimes present as rudiments. The larger number of species belong to the genus Ti/p/tlops. The Typhlopid.e are very generally distributed over the FiG. 209.-Head of T^pMops. ^^,.j^g,. portions of the globc, four species being found in our country north of Panama. To the naturalist they are most interesting forms and are eagerly sought after. They are the lowest as well as the smallest ophidians, — an ordinary earth-worm is gigantic when compared with some. Their short muscular body, designed for underground tunnellijig, rudimentary eyes, and peculiar dentition, are s]iecial points of interest. The genus Tij}Mops has the body covered with small imbricate scales ; the tongue forked ; a pair of scarcely discernible eyes ; and the lungs unequal in size. The head may be obtuse, depressed, or in some species drawn out into a horny tip ; the tail may also be en- sheathed in horn, as is the case with Tijpldops phiUppin^is. The upper jaw is toothed. Many species of this gemis inhabit British India, wliere, after showers, they come above ground and are very active. SERPENTS. 353 Of thf four Amoricim species, T. hiif/issl/iix.i is a doulitfiil form, whicli lias not boon iiK'l witli since tlio lime of its desoriptiou by Dumi'ii'l ;in(l IJibioii. T. penlUtis and T. fiKsiniaculatus are Mexican forms in which tlie eyes are invisibU'. The gen- eral color of tlio latter is yellow, but the more dorsal scales are minutely spotted at their bases, while the head and tail are immaculate. 7'. cmunctus is very long and slender, though the tail is not longer than the diameter of the body. The color is silvery brown, the snout and lijis light yellow. It is found from Panama northward. Australia has nearly a dozen species of this genus, most of which have been named after men who have distinguished themselves as herpetologists. They are all utidcr- ground forms, chiefly feeding on ants and their eggs. lu burrowing they are greatly facilitated by the general form of their body, which is of a larger diameter i)osteriorly and is terminated by a short acuminate tail. A second genus, Anomalepsls, characterized by having the crown shields reijularly arranged, is found in Jlexico. A. mexicamis is long and slender, with tail like Ty- phlo])s, and eyes visible through the semi-transparent ocular shield. The labials are only two in number, though the previous genus is ])rovided with four. The color is reddish-brown, of a lighter shade below; the yellowish-white border of the individual .scales gives the animal the apjwarance of being reticulated. The genus Stenontonia is provided with teeth in the lower jaw, and the shields of the crown are reduced to scales. The ocular is large and transparent, displaying the eye beneath. Members of this genus are quite abundant in ]\[exico, a form having the scales arranged in four- teen longitudinal rows, the two labials sej)arated by the ocular, and the infra-labials four, inhabits Texas, and is known as S. dalce. Allied to this is S. rubelluni, which has five infralabials and reaches a length of eight inches. SuB-OrDEU II. — COLUBRIFORMTA. This group embraces all the harmless ophidians except the forms already treated under the head of Opoterodonta. As a general rule these serpents have the maxillary and mandibulary, as well as the palatine and j)terygoid bones, well jn-ovided with small recurved teeth, and in some forms those of the mandible, posteriorly, may become fang-like and conduct poison from a venom gland. Such forms are, however, rare, and, though evidently poisonous, are not regarded as being dangerous. The sev- eral members present a great variety of form, and can more easily be distinguished from other sub-orders than they can be comprehensively defined as members of a single group circumsci'ibed by distinctive characters. The colubriform snakes are found in the temperate regions, usually as terrestrial forms, while in the trojiics they are not only found on the ground, but many are arboreal. Aquatic forms are abundant in some localities. Xot onlv are colubriform snakes beneficial in destroying vermin, such as mice and rats in the southern states, and the troublesome )iouched-gophers, Geomi/s bursariug, in the West, but some of these in- nocuous forms do not hesitate to battle with the most jioisonous Solenoglyphs, which they often defeat. As before said, though the majority of colubriform snakes are harmless, and are only too glad to retreat from the sight of a human being, a few are aggressive. Some of the tree-snakes, Dendrophida', do not hesitate to si)itcfully attack travelers as tliey j)ass unsus])ectingly through the jungles, and often — as they choose the eye as the point of attack — inflict dangerous wounds. The pythons have been known to attack vol.. 111. — 23 354 LOWER VERTEBRATES. and kill full-grown men by their powerful colls, though those reptiles nre ordinarily of a most timid nature, retreating on the least disturbance. The variations in form jsresented by the sub-order have their extremes in the short thick body of the Tortri- cidse, or the bluntly terminated body of Silt/bura, and the slender elongated form pre- sented by many of the Dendrophidie. A few, such as the pythons and boas, and some of the Eryeidaj, as well as the Tortricidse, have the pelvic limbs represented by a pair of anal claws. The first to be treated, and, consequently, the lowest family of colubriform snakes, includes a number of Asiatic underground forms, having many characters in common with the Typhlopidae, nnited under the name Uropeltid-e, or shield-tails. The mem- bers of this family have the cylindrical body passing without any visible constriction into the short pointed head. The tail is abbreviated and often terminates abruptly in a naked disc, or, in the genus Silybura^ covered with keeled scales. The eyes are very small, and the cleft of the mouth of inconsiderable width, and not distensible ; the jaws are armed with but a small number of teeth. The shield-tails, it will thus be seen, are adapted for an underground life, where they find larva?, worms, and ants' eggs, of which latter they are very fond. Though seldom met with, they are very abundant in numbers, and chiefly inhabit the island of Ceylon, though some forms are found on the neighboring mainland. The genus Uhlnophis includes several Cin- ghalese species, characterized by having the nasal plates separated by the rostral ; and the tail, which is shorter in the female, covered by smooth scales, and terminated by a rough shield. JR. oxi/7-hi/nchtcs reaches a length of fifteen inches, and is found in the loam at a depth of two or three feet, as well as in ant-hills. Ji. punctatus, which attains the length of nineteen inches, is the largest species. Of the genus Ui-opeltis, only a single species, U. grandis, the largest of the family, is known. It inhabits the mountains of Ceylon and is extremely rai'e. The genus Silybura includes a number of species which have the scales of the abrupt tail strongly keeled, and the supra-orbital and postocular shields confluent. S. macrolepis is represented by a single Indian sjiecimen measuring ten inches in length. Plecturus has only two uninteresting forms. The final genus of the Uropeltidre contains but a single species, Melanophidium vi/naadense, which has the termination of the tail armed with a rough horny point. The genus and species have been described from a specimen captured at Wynaad at an elevation of 3,.500 feet. The second family, Tortricid^, or short-tails, have the short, blunt head depressed, and not distinctly marked off from the bod}', which is protected by evenly laid, smooth plates, those of the ventral side exceeding the others but little in size. The eyes are small; the labials but six in number; and the teeth are few but stout. The most noteworthy feature, however, is the rudimentary pelvis, which bears a pair of small limbs which make their appearance each side of the base of the tail as small claws. Meml)ers of this family are found in both hemisphei'es, where they pre- fer the dry and sandy districts, burrowing near the surface for subterranean worms and insects. TortrLv scytule is beautifully banded with black, and does not exceed two feet in length. Its habitat is the valley of the Amazon, the natives often wearing it as an animated neck-ornament. T. eryx inhabits southern Europe and Egypt. The genus Cylindrophis is characterized by the absence of intermaxillary teeth. But three species arc known, two of which inhabit Britisli India, where, being, like the other members of the family, sub-terrestrial, they are seldom found. To the family Toitricidae may be appended the genus Xenopeltis, to which some SERPENTS. 355 naturalists give a family value. Xenopeltis has eight labial plates, and the ventral scales well developed ; it is rei)resented by a single species, X. unicohr, which inha- bits Borneo, Sumatra, Java, the Celebes, and otlier neighboring islands, as well as a portion of British India. In its habits it is nocturnal, and obtains its prey of small mammals by entering their burrows. Being a large and stout animal, sometimes reach- ing the length of four feet, it has little difficulty in overpowering its victims. The third family embraces the Ekvcid^, or sand-snakes. Members of this group have a small conical prominence on each side of the vent, somewhat resembling the anal spurs of the Boida^ ; the tail, however, is much shortened, and, instead of being Fig. 210. — Eryx jaciUus, saiid-suake. used as a prehensile organ, is so developed as to act as a lever, assisting the animal in working its way into the coarse gravel of the barren jilains which it inhabits. Nearly every desert has its representatives of these most interesting reptiles: America has Charina jdumbea. J^ri/.vjacidi(S is restricted to .southern Europe and Persia, while in India is found the harndess JSiu/.rjohnil, which the serpent-charmers so mutilate about the short, rounded tail, as to give the animal the ajipearance of having a posterior head, — a monster regarded with the utmost horror by the ignorant natives. In confine- ment this Indian form constantly remains hid in the gravel of its cage, from which it cannot be induced to appear, e.\eept by offering it the most tempting morsels. In its native haunts, the treeless deserts, the animal is probably creptiscular, as its food — mice 356 LOWER VERTEBRATES. and small reptiles — is much more abimdant at evening, or during tlie early moi-ning, than under the enormous heat of a nearly vertical sun. We now come to those ophidians, Pythonid^, which, because of their great size, have been known from the time of the earliest writers. Though of dimensions large cnougli to satisfy the cravings of the ordinary searcher after the marvellous, they liave nevertheless been the subject for most exaggerated stories, and it is extremely diffi- cult to find data which liave not been more or less subject to the influence of imagina- tion. The ancient writers were especially fond of magnifying the powers of these serpents. Valerius Maximus writes: "And since we are on the subject of uncom- mon phenomena, we may hei-e mention the serpent so eloquently and accurately recorded by Livy ; who says, that near the river Bagrada, in Africa, a snake was seen of so enormous a magnitude as to j)revent the army of Attilius Regulus from the use of the river; and after snatching up several soldiers with its enormous mouth, and devouring them, and killing several more by striking and squeezing them with the spires of its tail, was at length destroyed by assailing it with all the force of military engines and showers of stones, after it had withstood the attack of their spears and darts : that it was regarded by the whole army as a more formidable enemy than even Carthage itself; and that the whole adjacent region being tainted with the jiestilential effluvia proceeding from its remains, and the waters with its lilood, the Roman army was obliged to remove its station : he also adds, that the skin of the monster, measur- ing 120 feet in length, was sent to Rome as a trophy." Krefft, alluding to this jiicce of rem.arkable history, s.ays; " Snakes 10 to 14 feet long are considered very large now- a-days, and in former ages may have kept armies at bay, but our better acquaintance with their habits enables us to tre.at them with the contempt they deserve." Not only has the size of these animals been exaggerated, but their swallowing powers have, in some works, appeared as almost unlimited. The animals on which the pythons ordinarily feed are seldom larger than a small dog, and though they may seize and overpower animals as large as a goat, to swallow them " horns and all " is absolutely impossible. The Pythonidas, in general structure as well as i)i their habits, resemble the Boajidae, though they are all Old World forms, and have some of the labials deeply pitted, a characteristic which at once determines them. There are skeletal characters also which can be made use of in identification. In the boas the frontal bones are broader than long, while the opposite holds for the pythons. The rock-snakes, or Pythonidas, inhabit tropical Asia, Africa, and Australia, and though accounts are not rare of their attaining the fabulous length of forty feet, specimens bv actual measurement very rarely reach one half that length. The body is rounded; tail prehensile; head de- pressed and rounded in front ; eyes of moderate size, the elliptical pupil having its longer diameter vertical ; scales smooth, subcaudals in two rows ; some of the labials are pitted ; teeth on the intermaxillary, maxillary, palatine, pterygoid and mandibulary bones and none grooved; and the adults are provided with rudimentary hind limbs, placed each side of the vent, and called 'spurs.' These organs are suj^posed by the natives to be used in fighting, though they probably have sexual functions, or may be of use in grasping the limbs of trees as the animal swings over the surface of the water. Pythons generally prefer those localities which border on some quiet pool, where they lie in wait, either suspended from an overhanging limb, or hid in the luxurious vege- tation of the ground, or possibly partly submerged in the Mater, waiting the arrival of some small animal, which, as it is about to drink, the reijtile seizes by the snout. ^(/^rtfjt^. r-7g/7^^?,gS Eunectes viurinus, anacomla. SERPENTS. 357 and, after wrapping sevoral eoils of its body about it, strangles. Finally, having crushed the larger bones, the jiroee.ss of deglutition is begun, which may last for sev- eral hours; the head invariably being the first to pass into the gullet, the body follow- ing. As the teeth all point inwards, and the jaws are successively and alternately jnished forward and drawn back, the jirey, if not too large, is thus of necessity drawn into the mouth. The reptile may, however, iiiid that its food is not suitable, or it ma}^ need to take breath, and though the ])rey has passed some way down the oesophagus, it is not unfrequently disgorged, making its ajipe.-u-niice as a most frightfully contorted mass, covered with mucus from the alimentary tract; its slimy appearance having un- doubtedly given rise to the false notion that the animal covers its prey, previous to deglutition, with saliva. For some time after the reptile has taken a large meal, it is, either from fatigue or from the effects of so loading its stomach, extremely lazy and inactive, being not infrequently quite indifferent to what may be going on about it. The inactivity of menagerie sjiecimens, however, is due rather to the enfeeliling effect of a cold climate, rather than torjior resulting from overfeeding, or gentleness from kind treatment. It is in their native forests that these forms must be studied to be admired. Not only are the caged animals inactive, but the purple bloom, so charac- teristic of the healthy animal, is invariably defective or lost ; the rough treatment to which they are subjected, as well as a disease of the jaw, — caries, — rendering them indifferent and unhealthy. It is not an unusual occurrence for the female python, which exceeds the male in size, to deposit her eggs while in confinement and watch over them with the most zealous care. Observations have been made which prove that the eggs are actually incubated. The mother, after arranging them in a convenient pile, coils her body, the temperature of which is consideraljly above the normal, around and over them, remaining in this position until the eggs, at the end of about three months, are hatched. "We have here among the reptiles an undoubted instance of maternal solicitude. Python reticidatus has the following characteristic marking. The undei-Iying color is light yellowish-brown or olive, and the head and neck is ornamented bv a dark brown line passing from the tip of the snout backwards, on each side of which are two bands passing from the eyes to the angles of the mouth. Along the back a series of black rings bordered with white, spotted scales gives the animal a netted ap])ear- ance, from which it has received its specific wmwc, reticulatits. The netted ]iython is found quite abundantly in nearly all the islands of the Malay Archipelago, as well as in Burmali and Siani, where it is called Ular Sawad. Mr. Wallace, in his description of these islands, gives an account of a python which illustrates the bold and independent yet helpless nature of this, or a closely allied, mammoth seri)ent. It seems that during the evening, while the naturalist was interesting himself with his books and insects, a 2iython took up its abode in tlie thatched roof directly over the bed, not making its presence known, however, until the following afternoon, when it was fin.ally dis])Osed of by a native well accustomed to its habits, though it evinced all the indignation of a regular tenant. Pi/thon molurus, the adjiger of the Hindus, inhabits the peninsula of India as far north as the Himmalehs and also possibly the Malay peninsula and Java. Like other members of the family, it prefers tlie low moist lam's in the neighborhood of water, where it captures birds and small quadrupeds, such as fawns and rodents. It differs from the pi'evious species in several i)articulars. P. molurus has the two anterior ujijier labials, and four of the lower labials, deeply dented with pits, while P. reticio- 358 LOWER VERTEBRATES. latus has four upj^er and several lower labials similarly develoi")ccI. P. molurus has its light, greyish-browu body ornamented with a dorsal row of large square spots, below which are two lateral rows. The top of the head is ornamented with a lance- shaped blotch, along each side of whicli lie a pair of dark brown lines, which pass from the nostrils, through the eye, to the sides of the head, where each meets a simi- lar streak from the lower jaw. Python regia, the royal rock-snake, having the four anterior upper labials pitted, ^5Z:1-" ■ 7^;/,aH^^'^' Fig. lill. — I'ython seba, fetich-suake. and the lower labials broad and four in number, inhabits western Africa. It is of a dark brown color, almost black, and has a series of light spots along the middle of the back, and two more along the sides, beneath, the lips and chin are white. This python is quite often seen in menageries and traveling shows. P. 7iatalensis, the Natal rock- snake, is regarded with respect by the natives, believing that it has some mystic influ- ence over their destinies. It lives on small quadrupeds, remaining quite torpid for some time after its meal. At this time it is quite easily disposed of. P. sebce is a SERPENTS. 359 form oftoii nu't with in zoological gardens, where it is known as the fetich-snake. It8 home is in thu warmer parts of Africa. In Anstralia tlit're are at least six species of Pythonitla; and more genera than of any other innocuous family. The representatives are the largest ophidian inhabitants, some reaching the length of ten feet. They are nocturnal and move during the day only when compelled to. The genus Morelia has the rostral plate, as well as the ante- rior three labials and the j)osterior infralabials, provided with deep pits. M. spilotes is of a glossy black color, with a bright yellow spot on every scale ; the abdominal scutes are yellow, with shades of black. This animal may be distinguished, as can the other Australian rock-snakes, from the numerous poisonous forms inhabiting the same country, by the large number of scale rows, there being from forty to fifty in the pythons, while the largest number known among the jioisonous snakes is twenty-six. It is a strange coincidence that while the so-called 'Iue 31ountains, but is re])resented further west by the following species. The indiviiluals of this species inhabit nearly every region that offers shelter, though stony ridges supplied with trees and well watered seem to l)e their favorite localities. It is in such jtlaces that they can iind young water-rats, {Ilydrotmjs) ducks, and possibly the straying chickens of a neighboring farmer. Though naturally unobtrusive, when irritated they bite severely. The eggs of either this or the following species have Vjecn found. They were neatly piled up in a nest of dry grass, which was concealed in a hollow log. 31. variegata, or the carpet-snake, closelv resembles the diamond in its habits and structure, though its habitat is defined and separate. It is found in every other part of the continent except southern Vic- toria, the region of the diamond snake. In coloring it is of a uniform greenish brown with irregular markings ; different specimens show a great variation due to age and localitv. In their movements and general habits the carpet and diamond snakes are shnilar, though the former may be somewhat the larger. The genus AsjykUotes has the scales in fifty-two rows and reaches a length of eight feet, and may possibly grow larger, even exceeding the Jlorelias in size. The species are not well known, and only a few spcciniens have been captured. A. nielanocephctlus is at once recognized by its jet-black head and neck, its siuall scales, narrow abdominal plates, and the absence of pits in the labials. The general color is light brown, with darker rings above, and yellowish white below'. Allied to this genus is Liasig, the representatives of which have some of the upjier and lower labiuls pitted. The few species are found in the islands of the Arafura sea. Xardoa has only the posterior infralabial pitted. X. gilhertii has a length of from three to six feet. Of its habits little is known. Of the family of boas, the Boid.e, it may be said that its members are distinc- tively Xew World, resembling the jjythons in their h.abits, and in being of enormous size, but differing from them in several structural particulars. The boas have tlie I)ody long and fusiform ; the head distinct and flattened ; the snout ]>rominent ; the tail generally j^rehensile ; the nasal plates may be entire or divided ; the nostrils lat- eral. The labials are generally withotit the pits so characteristic of the Old World forms, many of the cejjhalic shields are divided, and the sulwaudals are entire. Boa impcrato); or the emperor, is found in Central America and ^lexico, ami may 360 LOWER VERTEBRATES. possibly be regarded as a northern variety of the more tropical Jioa constrictor, though the scales of the head are ratlier large. The general color is brownish, with a dorsal series of quadrangular brown spots, which is separated from the smaller spots of the flanks by a pair of light lateral lines. 7>. constrictor, though properly an inhabi- tant of Brazil, is represented in Central America by a variety, isthmica. Along the back is a series of transverse brown bands, each connected with the marks of the flanks by a latero-posterior isthmus, and along each side of the belly is a series of more ^^"^"^ W H I it w vA'i V 7'"/ .?■ ' J" Fig. 212. — Boa constrictor, or less broken, irregular sjiots of a black color. B. mexiccma is allied to B. imperator. B. constrictor, proper, iidiabits the more tropical ]iortions of South America, though travelers from all parts of the world have almost in\ariably described large serpents which have come under their notice as 'Boa-constrictors,' rendering it extremely difHcult to determine acurately what species they are describing, and bringing the name to so gener.al a use that it has almost lost the primary significance given it by its original propounder, Linne. SERPENTS. 361 Eunectes murimis, the anaconda, is also a native of tropical America, and is repre- sented in the engraving as in its native haunt, the low land hy some j)Ool or sluggish stream, about to seize a ' boat-bill.' Tiie anaconda is one of the largest representa- tives of the family, and is beautifully ornamented over a groundwork of rich brown, by a double series of blotches along the back, ami with irregular annular spots along the sides. I'IG. lilu. — Jilij/lwauiiia caninum, dog-he:ided boa. JCipfiosouM caninum, or the dog-headed boa, inhabits Brazil, and is of a green color with light dorsal bands. The labial 2)lates resemble those of the pythons in being deeply pitted. Epicrates cenchrta, the ringed boa or abonia, was at one time worshipped as a god by the ancient Me.vicans, who often offered to it human sacrifices. In its habits it is a true member of the family, strangling its prey by winding around it fold on fold of its ponderous bodj'. Its general color is of a dark yellowish gray, oriiainented with a dorsal row of large brown rings, and along the sides liy \ ariable blotches of a dark color, having in their centre a lighter crescentric ornament. 362 LOWER VERTEBRATES. A lar^e number of the smaller serpents are imited under the name Caiamarid^, or dwarf-snakes. The members of this group are found in nearly every country of the globe, living beneath stones and prostrate logs. Their diminutive size and nondisten- sible neck compels them to restrict their diet to such small grubs and worms as they can easily master and swallow ; while they are thus employing themselves they not infrequently become the prey of some larger foraging reptile. The genus Calamaria which is only found in the East Indies, has the labial plates reduced to four or five. Thouo-h there are several species, they resenible each other so closely that they can be classified only after considerable trouble. The Ulapes are their particular enemies. The genus Geo^Ms is represented in America by four species, all of which inhabit Mexico, where are also found the genera Ficimia, CheilorJiina, Stenorhina and TaTv- tilla. Virginia striatula is a little snake found in the south, from Virginia to Texas. Fig. 214. — Calamaria aWivcnhr. It is a modest and most inoffensive reptile; its reddish-brown back and salmon-colored inferior surface form a combination far too pleasing to be hid away, as it too often is, beneath the bark of some old dead tree or log. The genus Carp/iophis is very generally distributed ; in the United States, the species ammna, inhabiting the more eastern and northern portions, as the thunder, gi-ound, or worm-snake, is most familiar. In its habits it is nocturnal and sub-terres- trial, being much more often turned up by the plough, or brought to light by the hoe, than seen naturally on the surface. It, moreo\er, always seeks escape by burrowing, rather than by flight ; indeed, the animal's motions, when out of its element, are most awkward. In general coloration it resembles the previous species. The East Indian OUgodorus belong to this family, and are characterized by the absence of palatine teeth, and by their peculiar physiognomy, the head being short and blunt. Closely resembling the OUgodorus, externally, are the members of the genus Simotes, which, SERPEXTS. 363 however, have an armature of palatine teeth, and roach a consi/i is, which is represented by one of the most beautifid, as it is one of the most familiar, reptiles, the green-snake, Cydophisvenialis. This is a most gentle and harmless ophidian, allowing itself to be handled in the roughest way, and seldom offering the least ojiposition. Specimens are often captured and made pets of, living in confinement for considerable periods of time. In nature they are found in moist meadow-lands, where they are concealed by their protective color, and where they find an abundance of insect life well suited for their food. The green-snake is not oidy found on the ground, however, but is an active climber, and may not infrequently be seen entwined among the branches of bushes or of low trees. The genus is represented in India by a much larger form, C. major, which sometimes exceeds three feet in length. Closely related to Ci/clophis is the genus Merpetodri/as, representatives of which are found in both hemispheres. They are elongated forms, adapted to an arboreal life, their colors, shades of green and brown, being well adapted to conceal tlu'm. If. carbmtus is found in Brazil and Surinam, and is peculiar in that it has no vertebral row of scales, the several series of the body always being in an even numl)cr. The genus Coluber has many interesting forms, native as well as exotic. The Alleghanian variety of C. obsohtiis, the mountain black-snake, has received considera- ble attention, from its distribution. It was first detected in New England, along the Connecticut valley, where it attracted attention as a black-snake having the scales keeled, the ordinary Bascmiium coiistrictorhny'uv^ the scales smooth, and though since found in cither eastern localities, its proper home is among the mountains of the A])pala- chian range, where it sometimes reaches a length of seven feet. In confinement its tem- perament is (juite different from that of its smooth-scaled cousin, being mild and gentle. C.giittatus, the corn-snake, inhabits the southeastern jiart of the United States, and was first described, in 174.3, by Catesby, as follows: "It is all over beautifully marked with red and white, which seems to have given it the name of corn-snake, there being some maize or Indian corn much reseml)ling this in color; they are robbers of hen-roosts, otherwise they are harmless." In its habits the present form differs from the majority of our common snakes in being crepuscidar, sjiending the day hid away in some crevice. In length the coni-snake sometimes reaches five feet. This form has been a great stumbling block to herpetologists, having been described under a dozen different 366 LOWER VERTEBRATES. names. C. vulpinus, the fox-snake, has been captured in Massachusetts, though its home is further west. C. quadrivittatus, or chicken-snake, as it has been called by the negroes, frequently enters the southern cabins for rats and young fowl. The body is of a dark olive color, ornamented with four longitudinal brown bands. Of exotic Colubers, C. coreas, of Surinam, is the largest, and C. quater-radiatus, the largest of Europe. The iEsculapian-snake, C. cesadcqni, is the most common European type. Often they are seen in museums and menageries, where they become very tame. This form was introduced into the mythology of the ancients, who twined it around the staff of ^'Esculapius and the caduceus of Mercurj", which, when thus equipped, were supposed to be jiossessed of the most wonderful virtues. The genus Hascanium is i-epresented in North America by five species, and twice as many varieties. The most characteristic, as well as the most familiar form, and the common black-snake, _Z>. constrictor, inhabiting the United States east of the Rocky Mountains, and its variety, vetiistum, west to the Pacific, while nientovarius extends further south, through Mexico to Tehuantepec. The common black-snake is most often found in the neighborhood of water, and is particularly partial to thickets of alders, where it can hunt for toads, mice, and birds, and, being .an excellent climber, it is often seen among the branches of small trees and bushes, hunting for young birds in the nest. While on these plundering expeditions the reptile is often followed by a troop of small birds in the greatest flutter of excitement. The black-snake does not always rem.ain in unfrequented localities, however, but is often surprised in old fields, by the roadside, and will even enter barns and seize chickens. At these times, the rapidity with which it retreats, on Ijeing surprised, has given the animal, in some local- ities, the name of ' racer.' As long as retreat is offered there is no resistance, though if cornered, or during the breeding season, the usual mild temper gives place to a most irascible disposition ; this is very characteristic of the animal when in confinement, as it is alw.ays quarrelling and biting its fellow-prisoners, as often as the opportunity pre- sents itself. The racer has been known to follow people, though this is more generally from a spirit of investigation, rather than from any design on the part of the animal to attack the object of its pursuit. Dr. Yarrow, however, knows of an instance in which a female, with its young, on being surprised by a small girl, entwined itself around the child's neck, biting her, meanwhile, in the face, and would probably have strangled her, were it not for the timely arrival of assistance. The young of this species are peculiar ; instead of being black, as is the parent, they are of .an olivaceous color, ornamented with a dorsal series of dark-edged brown spots, M'ith lateral rows of spots of still darker color. The head is a dark chestnut shade, mottled with brown. Pennant's early description of this form illustrates the tendency to exaggerate, evinced by many old writers ; an inclin.ation, by the way, which has not entirely passed by. He says : " Many ridiculous frights have happened from this innocent reptile. As everyone in America is full of the dread of the rattle-snake, they are apt to fly at the sight of any of the serpent kind. This pursues, soon overtakes, and, twisting round the legs of the fugitive, soon brings him to the ground ; but he happily receives no hurt but what may result from the fright ; all the mischief this species does is to the housewives, for it will skim their milk pans of the cream, and rob their hen-roosts of all the eggs." Closely related to the black-snake is the coach-whip snake, B. Jiafjelllformis, which inhabits the south, as far west as the Mississippi, where its variety, testaceum, extends SERPENTS. 367 to the Pacific. The general form is greatly elongated, resembling in this respect some of the Dendrophidre, as specimens are sonietinics six feet in length. They are most beautiful animals, and so fleet in their movement as to almost fly over the ground. Though ordinarily inoffensive, on being attacked they defend themselves with vigor. Batram, in his " Travels in Carolina," speaks of once finding a hawk so wound up by one of these serpents as to be rendered almost helpless. The name ' coach-whip ' is not given because of the elongated body, Ijut from the arrangement of the juxtaposed caudal scales, which resemble a braided raw-hide whip. Catesby mentions a peculiar belief, among the Indians, that the snake will, by a jerk of its tail, separate a man in two parts; and the negroes of the south, to-day believe that it can flagellate a man to death. H. tetiiuturn is found from the plains to the Pacific. While H. constric- tor has the scales of the back in seventeen rows, J3. teniatum has them in fifteen, and is, moreover, ornamented with a lirown dorsal band and with lateral lines of orange, red, or yellow. The inferior surface is anteriorly spotted with brown. The genus Spilotes is represented in North America by two species which differ from the members of the previous genus in having the teeth equal and smooth — the ' black-snakes ' have them larger posteriorly. S. couperi inhabiting the Gulf states and Georgia, from its enormous size, is the most interesting form. In coloring it is of a deep black, shading into yellow on the throat. It is known by the negroes as the indigo or gopher-snake, and, though sometimes reaching the enormous length of ten feet, it is never molested by them, as they suppose it to be, like the king-snake ( Ophio- hohis f/etulus), a mortal enemy to the rattler. Pitt/02)his has the scales keeled, the nasal plate divided, and the last abdominal jslate entire. P. rnelanoleucus, the i)ine or bull-snake, is found east of the Mississippi and south of the Ohio rivers, and it is particularly fond of the pine forests. Though one of the largest North American serpents, it is extremely active, disappearing almost instantly on being surjiriscd, though this may be due to the fact that it not unfre- quently has underground holes into which it retreats, and from the immediate vicinity of which it seldom journeys. To obtain its prey it chooses a likely locality, and waits in patience for some unsuspecting rabbit or squirrel to pass by. P. hellona inhabits the west, feeding, as do many of the genus, on mice, gophers, and other small vermin, and doing, in this way, immense benefit to the agricultural interests, as the. gophers, as well as other small rodents, are perfect pests of the western farmer. The western bull- snake not inifrequently exceeds the length of six feet, but it is of a peaceful disposi- tion. Captured individuals of this species have been known, even when concealed, to attract others. It is not an unusual occurrence for the mate of a serpent which has been killed to search for, find the body, even when it has been dragged for some dis- tance, and remain by it apparently with a feeling of sorrow if not of revenge. The Indian rat-snake, Ptyas mucosuit, is very abundant in southern India and Ceylon, where it often enters human dwellings while in pursuit of rats or chickens. It is always ready, on the slightest irritation, to bite, and, as it grows to a considerable size, often reaching seven feet in length, it gives considerable annoyance to the natives. When angry, the rat-snake is said to produce a ])eculiar musical note not unlike that of a tuning-fork. In general structure it resembles our common black-snakes. The genus Dromiscics is common in the West Indies, South America, and Mexico. A single species, D. Jlavilatits, has been found in the southeastern United States, there being in the National IMusetnn a single specimen from Florida, and a second from North Carolina. D. atcr is the 'gray-snake' of Jamaica, and is ufteu seen about 368 LOWER VERTEBRATES. old ruins, lurking in some cranny for the approach of an unlucky lizard. If irritated, it will dart at its adversary with all the savage vehemence of the most venomous moccasin, and, as it sti'ikes for the eyes, its attacks not unfrequently prove dangerous. Zamenis includes those Old World snakes, found about the Mediterranean and iji India, which generally have the last ma.xillary tooth enlarged and separated from its fellows by a short interspace. Of the genus JTenehiphis but a single species has been described ; a few specimens, some measuring six feet in length, have been captured in the East Indies. Philodryas viridissimus, a most beautiful example of the Colubridje, and connecting them with the Dendrophidaj, inhabits Brazil, where, because of its slender body and beautiful green color, it has received tlie name of emerald whip- snake. It lives on young birds, and on such small prey as it may capture while meandering among the branches of the tropical forests. The members of the family Dexdeophid.e, or tree-snakes, are found sporting amid the luxuriant foliage of tropical America, Asia, and to a less extent, Africa and Aus- tralia. To adapt them for an arboreal life, the body and tail is greatly elongated, and each ventral scute is usually pro\ided with a pair of keels by which the animal can the more firmly grasp the smooth branches. The genus Deudroji/iis includes a large number of species, which are frequently adorned with the brightest colors, of which green is often the prevailing tint. The head, which is distinct from the neck, is nar- row, long, and depressed, the snout being very prominent. Two species, representing two genera, are natives of Mexico, Leptophis mexicanus, and Oxybelis ceneus, which latter species, though of small diameter, reaches a length of four feet. The Boom- Slange, Jiucep>habis capensis, of South Africa, presents so much variation in its mark- ing that several species have been described by those unprovided with a sufficient number of specimens. Though the inhabitants of South Africa consider this form to be poisonous, on dissection no venom glands have been found, though the teeth are covered with a slimy secretion, which maybe possessed of irritating qualities. Allied to Bucephalus is Ahcetidla liocercus, one of the most beautiful of tree-snakes, inhabiting Borneo, where the native children are said to often make a pet of it, the harmless reptile coiling around their arms and bodies without their evincing the slightest alarm and naught but pleasure. In its native haunts the animal is most active, leaping from branch to branch of the highest trees, and directing its lithe form with lightning celerity towards any unfortunate lizard or beetle which it may chance to espy. Liv- ing also in Borneo, as well as on neighboring islands, is the larger Goniosoma oxy- cepluduin., which reaches a length of eighty-two inches. It is said to be a most active and ferocious animal, defending itself, when attacked, with great energy. The tree-snakes proper are included in the genus Dendrophis, and are character- ized by having an obtuse snout, equal teeth, and smooth vertebral scales. Bendro- phis 2ncta is the most common East Indian form, and, like Bncephalus, it is liable to great variation in color. D. punctidata is a beautiful animal inhabiting Australia, and growing to a length of five or six feet. It is of an olive-green color above, and pale yellow below; the shades of color, however, appear to depend on surroundings, as specimens in captivity are never so brilliant as those seen gliding along the grass- land, or swinging from branch to branch of the lofty trees. The nearness to the time of exuviation has also considerable to do with the coloring; specimens just after the old epidermis is shed being very brilliant. The eye of this form is large ; the teeth small and of uniform size, and the dorsal row of scales considerably exceeds in size those of the scales of the body. A loreal, a scale generally characteristic of this as SERPENTS. 369 well ns of otlior innocuous ojiliidians, is present, and the assumed shape of the body wlien the animal is angry is coniiiressod, instead of dejiix'ssed like that of venomous forms, of whicli the laterally extended neck of the JSIcJa presents the best type. It seldom attempts to bite, and can be ordinarily handled without showing any re- sistance. The food consists of batrachiaus, saurians, young birds, and possibly insects. It is ju'obably oviparous, and is foun