PIKA indigenous ; usually they are met with in cul- tivated grounds and in the streets and waste places of towns. C. album, more generally known as pigweed than any other, is 1 to 3 ft. high, with leaves varying from rhombic-ovate to lanceolate, and more or less angled-toothed ; the plant is usually covered with a white meal- iness, though it is variable in this as in other characters. This is one of the many plants eaten by country people as " greens," and cooked when young is not a poor substitute for spinach ; it is often called lamb's-quarters in this country, a name which in England is given to a plant of a different but related ge- nus. Another species, C. Bonus- Henricus, was formerly cultivated in England for its large spinach-like leaves, and called good Henry or good King Harry and fat-hen. All of our pig- weeds are annual, and while they indicate slovenly culture, they can hardly be regarded as troublesome weeds. The genus gives its name to a family, the chenopodiacece, which includes also the beet, mangel wurzel, and spinach, and among flowers the exceedingly fragrant Boussingaultia, or Madeira vine, the leaves of which are used in France as spinach. PIKA (lagomys, Cuv.), a genus of the family leporidce, including the tailless hares. They have no visible tail, the ears are short and rounded, the hind legs short, and the molars flf ; the skull is very flat, dilated behind, the interorbital space contracted, the supraorbital processes absent, the orbits directed upward, and the malar bones extending backward near- ly to the opening of the ear chamber ; there is one principal opening in the nasal process of the superior maxillary bone ; the zygomatic arch is remarkably short ; the coronoid process of the lower jaw a mere tubercle, and the men- tal foramen situated near the middle of the ra- mus ; the principal upper incisors have a deep vertical groove on the outer side, and termi- nate in two points with a notch at the end ; the lower incisors simple ; the upper molars as in the hares, the lower with a deep outer groove ; there are generally small naked pads at the ends of the toes, the rest of the feet densely clothed with fur. The pikas are small, the largest not exceeding a Guinea pig ; they are found only in alpine or subalpine districts, where they live in burrows or among loose stones, remaining quiet by day and feeding at night; the food consists of herbage of differ- ent kinds, whict they store up in little piles in autumn ; when feeding they often utter a chirp- ing or whistling noise. The alpine pika (L. alpinus, Ouv.) is about 9 in. long, with long and soft fur, grayish next the skin ; general color above grayish brown, yellowish gray be- low ; feet pale with a yellowish tinge ; the ears margined with white ; it inhabits Siberia from the river Irtish to Kamtchatka. Other species are found in the mountainous districts of Hin- dostan, some of them 6,000 or 8,000 ft. above the sea. The Rocky mountain pika (L. prin- ceps, Rich.), or little chief hare, is about 7 in. 663 VOL. xiii. 33 PIKE 509 long ; the general color is grayish above, pen- cilled with black and yellowish white; yel- lowish brown on the sides, and dirty yellow- ish white below ; it is found along the Rocky J Kocky Mountain Pika (Lagomys princeps). mountains from lat. 42 to 60 N. ; it frequents heaps of loose stones, coming out after sunset. Three or four fossil species are described, from the osseous breccia and the pliocene of Europe. PIKE (esox, Linn.), the common name of the soft-rayed abdominal fishes of the family eso- cidcB. Their headquarters are in North Amer- ica, only one species being found in Europe and temperate Asia ; they are confined to fresh water and to the northern hemisphere. The body is elongated and scaly ; there is a single dorsal, generally opposite the anal, but no adi- pose fin ; the upper jaw is formed principally by the intermaxillaries ; the mouth is large and well furnished with teeth; there are several covered glandular accessory branchiae, the num- ber of branchiostegal rays varying from 3 to 18 ; swimming bladder simple; stomach siphonal, intestine short and without ceeca ; under the skin are vascular ramifications, peculiar to the family. According to Agassiz, the cylindrical elongated form indicates a low position among the abdominal fishes, as also does the mouth, the maxillaries being without teeth, while the palate bones are powerfully armed; the in- termaxillaries and the maxillaries are in one arch, as in the salmon family ; the skeleton, and especially the skull, is remarkably soft. The common pike of Europe (E. lucius, Linn.) rarely exceeds 3 ft. in length or a weight of 12 or 20 Ibs. ; some have been described con- siderably beyond these, but most are below them ; the head is elongated and flattened, the lower jaw considerably the longer; the gape very large; the head and upper back duskj brown, becoming lighter and mottled with green and yellow on the sides, passing into silvery white below; pectorals and ventrala pale brown, other fins darker, mottled with white, yellow, and green ; iris yellow. Young pikes, or pickerels, are of a greenish hue, and the colors vary much at all ages. The pike inhabits most of the rivers and lakes of Eu- rope, and was long ago introduced into Great Britain, where it is now exceedingly common ;
