Popular Birttonarg) of gmmatelr $aturr. 751 



sunny banks ; their cells are composed of | 

 earth, and are very smooth in the inside, and 1 

 the mouth of the nest is closed with the I 

 same material. Their wings are most com- ; 

 monly black, with a fine purple or violet 

 gloss. 



XYLOPHAGA. A genus of small Con- ! 

 chiferous Molluscs, very similar to those of 

 Teredo, and which are found in light wood 

 that the animals have penetrated to the 

 depth of about an inch. The valves are 

 equal, globose, inequilateral, and closed at 

 the back ; they have no calcareous tube, but 

 two small accessory testaceous pieces placed 

 near the hinge, and one small tooth in each 

 valve. 



XYLOPHAGI. A family of insects of the 

 order Coleoptera Tetramera, distinguished 

 from the Weevils by the absence of a pro- 

 boscis. These insects generally live in wood, 

 which is perforated and channelled in va- 

 rious directions by their larvse. The dif- 

 ferent species commit their ravages on various 

 kinds of trees, some feeding on pines and firs, 

 others on olives, and some restricting them- 

 selves to fungi. [See SCOLTTTIDJB.] 



XYLOPHILI. An extensive series of ; 

 gigantic Coleopterous insects, the males of 

 which are particularly distinguished by va- i 

 rious singular protuberances, horns or tu- j 

 bercles, arising from the head and thorax. 

 They reside for the most part in tropical 

 regions, and some of them acquire an immense { 

 size. [See DVNASTID.K and BtrnuDiA.] 



XYPHOSURA. A sub-class of Crustacea, ' 

 so called from the long tail-like spine, so i 

 characteristic a mark of the King-Crab, i 

 There is only one well-marked genus of this 

 group, which will be found described under \ 

 the head of LIMULUS. 



YAK. (Poephogtis grrwnnt'ens.) A species j 

 of Ox found in Thibet, among the mountains ; j 

 the bushy white tail is much prized in the 

 East, where it is used to brush away flies, 

 and also as an emblem of authority. 



YARKE. The native name of different 

 South American monkeys of the geims Pi- 

 thecia. 



YELLOWHAMMER. (Emberiza citri- \ 

 nella.) This Passerine bird, which is about I 

 seven inches in length, is found a resident in 

 this country, and generally throughout Eu- ! 

 rope. The male is known by the head, cheeks, 

 front of the neck, belly, and tail-coverts 

 being of a bright yellow ; on the breast and 

 sides reddish spots, which on the sides leave 

 a black streak in the centre. Feathers of the 

 top of the back, blackish in the middle, 

 and reddish-brown on the sides ; those on 

 the rump bright chesnut, terminated with 

 grayish ; tail-feathers blackish, the two la- 

 teral ones with a conical white spot on the 

 inner barbs. Feet yellowish. The ftmale 

 is smaller than the male ; and the yellow of 

 the head, throat, and neck more thickly 

 marked with the brown and olive spots with j 

 which those parts are sprinkled. Their food 

 consists of grain, seeds, and insects. In 

 summer the well-known notes of the male 



two behind ; the claws sharp, much hooked, 

 and formed for climbing branches of trees, 



an orme r mn rancs res, 

 on which it can run with the utmost facility. 

 The Wryneck is found in various parts of 



(WRYNSCK. (TONS. TORQOIIJ1A.) 



Europe, and generally precedes the Cuckoo 

 a few days. Its food consists chiefly of ants 

 and other insects, of which it finds great 

 abundance lodged in the bark and crevices 

 of trees. 



XANTHU. A genus of Brachyurous 

 Crustaceans, of which there are numerous 

 species, extensively distributed. The cara- 

 pace is very wide, but never regularly ovoid, 

 and not very convex. They are arranged by 

 Milne Edwards into those species whose 

 carapace if granulous or tuberculous above 

 and those species whose carrapace is not co- 

 vered either with granulations or tubercles. 

 One species, Xanthojhridus, about two inches 

 in length, of a i-eddish brown colour, with 

 black claws, is common on the English and 

 French coasts. 



X ANTHORNUS. The generic name used 

 by Brissou for certain American birds. [See 

 OKIOLE, BALTIMORE.] 



XENOPS. The name used by Illiger for 

 a genus of Fissiroetral birds of South Ame- 

 rica ; one species of which (Xenops geni- 

 barbis) is thus described by Mr. Swainson : 

 above reddish, beneath gray-brown ; chin, 

 eyebrows, and spots on the throat and breast 

 whitish ; beneath the ears a snowy spot ; 

 lesser quills blackish, the base fulvous, the 

 tips and margins rufous. Mr. Swainson 

 remarks that this extraordinary and not in- 

 elegant little creature has a bill totally dif- 

 ferent from that of any other bird. Its ge- 

 neral habit, he states, evinces a close con- 

 nection with the Sittse, particularly those of 

 New Holland ; some of which have their bills 

 (which are slender) slightly inclining up- 

 wards, thus forming a connection between 

 Xenops and the straight-billed Stitce of the 

 Old World. 



XIPHIAS. [See SWORD-FISH.] 



XYLOCOPA. A genus of Hymenopterous 

 insects, frequently termed Carpenter Bees, 

 from their boring holes in wood. They are 

 characterized by the very thick coating of 

 hairs upon the hind legs of the females, which 

 are used by them as pollen-brushes. They 

 form their nests in crevices of old walls or in 



