Page:Encyclopædia Britannica, Ninth Edition, v. 21.djvu/872

Rh 846 S H R S H R supposition that Aristotle's Tyrannus was another, as well as Belon's reference of Collyrion. The species designated Shrike by Turner is the Lanius excubitor of Linmeus and nearly all succeeding authors, nowadays 1 commonly known as the Greater Butcher-bird, Ash-coloured or Great Grey Shrike, a bird which visits the British Islands pretty regularly, though not numerously, in autumn or winter, occasionally prolong- ing its stay into the next summer ; but it has never been ascertained to breed there, though often asserted to have done so. This is the more remarkable since it breeds more or less commonly on the Conti- nent from the north of Franca to within the Arctic Circle. Exceeding a Song-Thrush in linear measurements, it is a much less bulky bird, of a pearly grey above with a well- denned black band passing from the forehead to the ear-coverts ; beneath it is nearly white, or and this is particularly observable in Eastern examples barred with dusky. The quill-feathers of the wings, and of the elongated tail, are variegated with black and white, but are mostly of the former, though what there is of the latter shows very conspicuously, especially at the base of the remiges, where it forms either a single or a double patch. 2 Much smaller than this is the Red-backed Shrike, L. collurio, the best-known species in Great Britain, where it is a summer visitor, and, though its distribution is rather local, it may be seen in many parts of England and occasionally reaches Scotland. The cock is a sightly bird with his grey head and neck, black cheek-band, chestnut back, and pale red breast, while the hen is ordinarily of a dull brown, barred on the lower plumage. A more highly coloured species is called the Woodchat, L. auriculatus or rutilus, with a bright bay crown and nape, and the rest of its plum- age black, grey, and white. This is an accidental visitor to England, but breeds commonly throughout Europe. All these birds, with many others included in the genus Lanius, which there is no room here to specify, have, according to their respective power, the very remarkable habit (whence they have earned their opprobrious name) of catching insects, frogs, lizards, or small birds and mammals, and of spitting them on a thorn or of fixing them in a forked branch, the more conveniently to tear them in pieces and eat them. The limits of the Family Laniidx have been very variously regarded, and agreement between almost any two systematists on this point seems at present out of the question. The latest synopsis is that by Dr Gadow (Cat. B. Brit. Museum, viii. pp. 88-321), who frankly states that it is " quite impossible to give a concise diagnosis of what we are to understand by" the Family. For his purpose he makes it to include about 250 species and divides it into five sub-families : Gymnorhininx, Mala- conotinse, Pachycephalinx, Laniinx, and Vireoninx. Of these doubts may be entertained as to the affinity of the first and especially of the last. He, but for the crude plan to which he was compelled to conform, would not have separated Strepera from Gymnorhina ; but the former had 1 According to Willughby, Rae, and Charleton, it was in then" day called in many parts of England "Wierangle" (Germ. Wiirgengel and W&rger, the Strangler) ; but it is hard to see how a bird which few people in England could know by sight should have a popular name, though Chaucer had used it in his Assembly >e of Foules. a On this character great store has been laid by some recent writers, who maintain that the birds presenting only a single patch, with some other minor distinctions, as the barred breast above mentioned, come from the far East and deserve specific recognition as the Lanius major of Pallas. But it is admitted that every intermediate form occurs, and Prof. Collett has now shown (fbis, 1886, pp. 30-40) that the typical L. excubitor and typical L. major may be found in one and the same brood, and also that this occasional divergence is due neither to age nor sex. That it does depend to some extent on locality is allowed ; for, though examples with the single patch (i.e.,L. inajor) occasionally reach Great Britain, it is asserted that nearly all the specimens from Eastern Siberia are so marked. But it is also found that by almost insensible degrees other (and sometimes more important) distinctions are mani- fested, and the extreme terms of the several series have been exalted to the rank of "species" or at least local races. These are too many to be here enumerated, but it may be mentioned that the Great Grey Shrike of North America, which ordinarily has the lower plumage strongly barred, and is usually known as L. borealis, seems to be only one of these divergent forms, though perhaps the most divergent, as might be expected from the wholly distinct area it occupies. Yet occasionally examples occur in the Old World, which there is no reason to suppose have an American origin, indistinguishable from the typical L. borealis, and an uninterrupted series from one extreme to the other can be found. The differences when compared with those observable in other animals are, as a whole, too slight to justify the epithet "poly- morphic " to L. excubitor as a species ; but enough has been said to show that it indicates a tendency in that direction. been already included, to the exclusion of the latter, among the Corvidx, and even placed among the normal Cortina;. The need of exercising reserve on this matter has been before stated (Csow, vol. vi. p. 617) ; but the number of ornitho- logists who think that these two genera should be placed in different Families must be small. The view taken by Prof. Parker seems to be the most reasonable : these genera with others doubtless and most of them Australian are morpho- logically inferior to the Corvidw, and perhaps deserve some such designation as that of "Noto-Coracomorphx" suggested by him (Trans. Zool. Society, ix. p. 327). At the same time their relationship to the Laniidse appears to be evident, and they may perhaps be best regarded as the less-altered descendants of an old type, whence both the true Crows and the true Shrikes have sprung, each to develop into higher morphological rank, and by the way to throw out numerous other branches. As to the Vireos it would seem almost certain that they have little or no connexion with the Laniidx. (A. N.) SHRIMP, the name applied to two species of Crus- taceans commonly used as food in Great Britain. One kind after boiling is brown in colour, the other bright red. The brown kind belongs to the species Crangon wdgaris, the red to the species Pandalus anmtlicornis. Both these species belong to the sub-order Decapoda, and to that division of it which is distinguished by a well- developed abdomen or tail, and called Macroura. The Crustaceans placed in this division have five pairs of limbs adapted for crawling on the sea-bottom ; usually the an- terior one or more pairs of these five are chelate or pincer- formed. In front of the ambulatory limbs are six pairs of limbs whose function is to assist in the conveyance of food to the mouth, three pairs of inaxillipeds, two pairs of maxillae, and a pair of mandibles. In front of these, again, are two pairs of antennae and a pair of eyes. The latter are held by some naturalists to represent a pair of limbs, but evidence exists which is in opposition to this view. Behind the ambulatory limbs are six segments of the body, each bearing a pair of limbs adapted for swim- ming. The sixth pair of these abdominal limbs are larger than the rest and expanded, extending backwards in the same plane as the flattened terminal segment of the body or telson, and the three together form a powerful organ of locomotion by which a rapid backward movement of the whole body in the water is produced. The genus Crangon is the type of a family, the Crangonidx. The most conspicuous characteristic of the genus is the shape of the first pair of ambulatory limbs. These differ less from the rest than is usually the case, and the terminal pincer apparatus is but slightly developed. The terminal joint is small, and the projection of the second joint against which it acts is still smaller, so that the cutting edges of the pincer are transverse to the rest of the limb. The second pair of limbs have also a terminal pincer apparatus, and both the second and the third are slender. The fourth and fifth pairs are short and thick. The rostrum, the median projection of the anterior part of the carapace, is rudimentary. The line joining the attachments of the two pairs of antennae are transverse to the axis of the body. The abdomen is large. There are seven branchiae on each side. The specific characters of C. vulgaris, Fabr., are the smoothness of the dorsal surface, the carapace presenting only three small spines, one median in the gastric region and one on each side on the branchi- ostegite. The second pair of ambulatory limbs are nearly as long as the third. The size of the adult animal is about 2 inches. The species is abundant on sandy shores at nearly all parts of the British and Irish coasts, and is captured by nets which have a semicircular mouth, and are attached to a pole wielded by a fisherman wading in the water at ebb-tide. The common shrimp is an exception to the general rule that the cuticle of Crustaceans is either red in the living animal or becomes so on boiling. The cuticle of C. vulgaris in the living state is light brown or almost white, and the animal