Sp, Anchoring spines of the statoblast.
In all these families spines and glandular papillae may be super-added.
The arrangement is perhaps derivable from a Cribrilina-like condition in which the outer layer of the spines has become membranous while the spines themselves are laterally united from the first.
As all these animals are killed by the poison of the snake before they are swallowed, and as their muscles are perfectly relaxed, their armature is harmless to the snake, which begins to swallow its prey from the head, and depresses the spines as deglutition proceeds.
The first dorsal fin and the ventrals are transformed into pointed formidable spines, and joined to firm bony plates of the endoskeleton.
The development of its scutes and spines varies exceedingly, and specimens may be found without any lateral scutes and with short spines, others with only a few scutes and moderately sized spines, and again others which possess a complete row of scutes from the head to the caudal fin, and in which the fin-spines are twice as long and strong as in other varieties.
The ten-spined stickleback (Gastrosteus pungitius) is so called from the number of spines usually composing its first dorsal fin, which, however, may be sometimes reduced to eight or nine or increased to eleven.
The sea-stickleback (Gastrosteus spinachia or Spinachia vulgaris) attains to a length of 7 in., and is armed with fifteen short spines on the back.
The body is enclosed in a stout cuticle, prolonged in places into spines and bristles.
The Cacti may be described in general terms as plants having a woody axis, overlaid with thick masses of cellular tissue forming the fleshy stems. These are extremely various in character and form, being globose, cylindrical, columnar or flattened into leafy expansions or thick joint-like divisions, the surface being either ribbed like a melon, or developed into nipple-like protuberances, or variously angular, but in the greater number of the species furnished copiously with tufts of horny spines, some of which are exceedingly keen and powerful.
High, the surface divided into numerous furrows like the ribs of a melon, with projecting angles, which are set with a regular series of stellated spines - each bundle consisting of about five larger spines, accompanied by smaller but sharp bristles - and the tip of the plant being surmounted by a cylindrical crown 3 to 5 in.
- This genus, which comprises nearly 300 species, mostly Mexican, with a few Brazilian and West Indian, is called nipple cactus, and consists of globular or cylindrical succulent plants, whose surface instead of being cut up into ridges with alternate furrows, as in Melocactus, is broken up into teat-like cylindrical or angular tubercles, spirally arranged, and terminating in a radiating tuft of spines which spring from a little woolly cushion.
The spines are variously coloured, white and yellow tints predominating, and from the symmetrical arrangement of the areolae or tufts of spines they are very pretty objects, and are hence frequently kept in drawing-room plant cases.
These large plants have from 40 to 50 ridges, on which the buds and clusters of spines are sunk at intervals, the aggregate number of the spines having been in some cases computed at upwards of 50,000 on a single plant.
Pilocereus, the old man cactus, forms a small genus with tallish erect, fleshy, angulate stems, on which, with the tufts of spines, are developed hair-like bodies, which, though rather coarse, bear some resemblance to the hoary locks of an old man.
The plants are nearly allied to Cereus, differing chiefly in the floriferous portion developing these longer and more attenuated hair-like spines, which surround the base of the flowers and form a dense woolly head or cephalium.
They are fleshy shrubs, with rounded, woody stems, and numerous succulent branches, composed in most of the species of separate joints or parts, which are much compressed, often elliptic or suborbicular, dotted over in spiral lines with small, fleshy, caducous leaves, in the axils of which are placed the areoles or tufts of barbed or hooked spines of two forms. The flowers are mostly yellow or reddish-yellow, and are succeeded by pear-shaped or egg-shaped fruits, having a broad scar at the top, furnished on their soft, fleshy rind with tufts of small spines.
The Tenthredinidae, or true saw-flies, are distinguished by two spines on each fore-shin, while the larvae are usually caterpillars, with three pairs of thoracic legs, and from six to eight pairs of abdominal prolegs, the latter not possessing the hooks found on the pro-legs of lepidopterous caterpillars.
In Halohates a comb-like series of sharp spines on the fore-shin can be drawn across a set of blunt processes on the shin of the opposite leg.
Males of the little water-bugs of the genus Corixa make a shrill chirping note by drawing a row of teeth on the flattened fore-foot across a group of spines on the haunch of the opposite leg.
Green mud differs to a greater extent from the blue mud, and owes its characteristic nature and colour to the presence of glauconite, which is formed inside the cases of foraminifera, the spines of echini and the spicules of sponges in a manner not yet understood.
Of the Ceylonese galls, " some are as symmetrical as a composite flower when in bud, others smooth and spherical like a berry; some protected by long spines, others clothed with yellow wool formed of long cellular hairs, others with regularly tufted hairs."
They are all stout, heavily-built animals, with blunt rounded heads, fleshy mobile snouts, and coats of thick cylindrical or flattened spines, which form the whole covering of their body, and are not intermingled with ordinary hairs.
The spines are mixed with long soft hairs.
They include three genera, of which the first is represented by the Canadian porcupine (Erethizon dorsatus), a stout, heavily-built animal, with long hairs almost or quite hiding its spines, four frontand five hind-toes, and a short, stumpy tail.
They are of a lighter build than the ground-porcupines, with short, close, many-coloured spines, often mixed with hairs, and prehensile tails.
The pollen grain bears numerous spines, the dark spots indicate thin places in the outer wall.
The body-wall is highly muscular and, except in a few probably specialized cases, possesses chitinous spines, the setae, which are secreted by the ectoderm and are embedded in pits of the skin.
The " postabdomen," marked off by the two postabdominal setae, usually has teeth or spines, and ends in two denticulate or ciliate claws, or it may be rudimentary, as in Polyphemus.
These have the furcal branches broad, lamellar, with at least three pairs of strong spines or ungues.
The skin is devoid of ossifications, but large and numerous cutaneous spines are often present, especially on the head and on the tail.
Their scales are mixed with larger prominent spines, which in some species are particularly developed on the tail, and disposed in whorls.
The body is uniformly covered with granular scales, whilst the short, strong tail is armed with powerful spines disposed in whorls.
Among the ammonites the loss of power to coil the shell is one feature of racial old age, and in others old age is accompanied by closer coiling and loss of surface ornamentation, such as spines, ribs, spirals; while in other forms an arresting of variability precedes extinction.
There is also the Moloch horridus of South and Western Australia, covered with tubercles bearing large spines, which give it a very strange aspect.
The cuticle is frequently prolonged into spines and papillae, which are especially developed at the anterior end of the body.
The lid is especially attractive to insects from its bright colour and honey secretion; three wings lead up to the mouth of the pitcher, on the inside of which a row of sharp spines points downwards, and below this a circular ridge (r, fig.
The gentle lemurs (Hapalemur) have a rounder head, with smaller ears and a shorter muzzle, and also a bare patch covered with spines on the fore-arm.
Zeisig and Zeising), long known in England as a cage-bird called by dealers the Aberdevine or Abadavine, names of unknown origin, the Fringilla spines of Linnaeus, and Carduelis spines of modern writers, belongs to the Passerine family Fringillidae.
18, 21 b); the body shortened, with the abdomen swollen, but protected with tubercles and spines, and with longish legs adapted for an active life, as in the predaceous larvae of ladybirds; the body soft-skinned, swollen and caterpillar-like, with legs well developed, but leading a sluggish underground life, as in the grub of a chafer; the body soft-skinned and whitish, and the legs greatly reduced in size, as in the wood-feeding grub of a longhorn beetle.
Aridity has favoured the production of spines as a defence from external attack, sharp thorns are frequent, and asperities of various sorts predominate.
It is almost made up of fragments of spines, teeth and scales of ganoid fish.
- " Errant" Polychaetes with well-marked prostomium possessing tentacles and palps with evident and locomotor parapodia, supported (with few exceptions) by strong spines, the aciculi; muscular pharynx usually armed with jaws; septa and nephridia regularly metameric and similar throughout body; free living and predaceous.
They are named " spines " or " spurs."
There are two dorsal fins, the anterior near the head, composed of 11-14 feeble spines, the second near the tail with all the rays soft except the first, and behind the second dorsal five or six finlets.
Others again, like Gasteracantha and Acrosoma, belonging to the Argyopidae, are armed with sharp and strong abdominal spines, and these spiders are hard-shelled like beetles and are spotted with black on a reddish or yellow ground, their spines shining with steel-blue lustre.
The body is ringed, and often has circles of spines, which are continued into the slightly protrusible pharynx.
The anterior edge of the dorsal fin is furnished with a row of small rounded horny spines or, rather, tubercles, of variable number.
Some species of Strophalosia and Productus seem also to have been moored during life to the sandy or muddy bottoms on which they lived, by the means of tubular spines often of considerable length.
The agreement of the grouping of the somites, of the form of the parapodia (appendages, limbs) in each region, of the position of the genital aperture and operculum, of the position and character of the eyes, and of the powerful post-anal spines not seen in other Arthropods, is very convincing as to the affinity wise suppressed praegenital somite.
38), like that of Limulus and Scorpio, and that lateral spines on the pleura of the somites are frequent as in Limulus, and that neither metasomatic fusion of somites nor post-anal spine, nor lateral pleural spines are found in any Crustacean, nor all three together in any Arthropod besides the trilobites and Limulus - the claim of the trilobites to be considered as representing one order of a lower grade of Arachnida, comparable to the grade Entomostraca of the Crustacea, seems to be established.
Having no spines to their fins, the Gadids used, in Cuvierian days, to be associated with the herrings, Salmonids, pike, &c., in the artificially-conceived order of Malacopterygians, or soft-finned bony fishes.
Fins without spines; caudal fin, if present, without expanded hypural, perfectly symmetrical, and supported by the neural and haemal spines of the posterior vertebrae, and by basal bones similar to those supporting the dorsal and anal rays.
Unlike sloths, the megatherium has seven cervical vertebrae; and the spines of all the trunk-vertebrae incline backwards.
The evolution of the arrangements for protruding the polypide seems to have proceeded along several distinct lines: (i.) In certain species of Membranipora the "frontal membrane," or membranous free-wall, is protected by a series of calcareous spines, which start from its periphery and arch inwards.
In Cribrilina similar spines C FIG.
Macmillan & Co., Ltd.) b, bristle; cs, caudal spine; ph, pharynx; s s', the spines on the two segments of the proboscis; sg, salivary glands; st, stomach.
These spines are used by the Mexicans as toothpicks.
In diameter, and distinguished by the presence of spines along the ribs of the shell.
They are composed of only from ' six to nine segments, which are beset with prominent spines, some of the latter appearing to be organs of special sense.
As indications that the conditions described in Membranipora and Cribrilina are of special significance may be noted the fact that the ancestrula of many genera which have well-developed compensation-sacs in the rest of their zooecia is a Membranipora-like individual with a series of marginal calcareous spines, and the further fact that a considerable proportion of the Cretaceous Cheilostomes belong either to the Membraniporidae or to the Cribrilinidae.