Ray, the name of the plagiostome, chondrop-terygian, or cartilaginous fishes of the suborder raiioe, popularly called skates. The numerous families are characterized by great flatness and width of the body, the latter arising principally from the extreme expansion of the pectoral fins; the skull is flat, the upper wall generally membranous, and movably articulated, as in sharks, by two condyles and an intervening space with the spine; anteriorly the head ends in a tapering cartilage which supports the snout; spout holes or spiracles for respiration and eyes on the dorsal aspect, the latter without lids or with an upper adherent one; on the ventral surface are five slit-like gill openings, before the ventrals and under the pectorals; the scapular arch is complete above and below, supporting the long, jointed, cartilaginous rays of the pectorals; between this and the pelvic arch, supporting the ventral, lie the abdominal viscera, and between it and the narrow skull are the branchial apparatus and the vascular centres.
The spiracles are openings by which the water may pass from the upper surface of the head into the mouth cavity, and are found in perfection only in those species which live upon the bottom; the eyes being above, and the fins feeble, they seek their prey by the sense of touch in the snout, stirring up the mud and sand while feeding; their gills would thus be injured by gritty materials were the water taken in from below by the mouth; in the rays the comparatively pure water enters from above by the spiracles, and passes out at the branchial openings, or vice versa. The development of these openings is in direct proportion to that of the sense of smell, and in inverse proportion to that of sight. (See "Proceedings of the Boston Society of Natural History," vol. xvii., November, 1874.) In the torpedoes the cellular galvanic batteries occupy the spaces between the skull and the pectorals; and a homologous rudimentary apparatus has been found in the tail of common skates, showing the adherence to a general plan of structure irrespective of function. The tail in some is fleshy and tapering, in others slender and cartilaginous, in others elongated like a whip lash, and in others armed with lancet-shaped spines on the upper surface, making a very formidable weapon.
The gills consist of membranous folds on plane surfaces, and the arterial bulb has from two to five transverse rows of semilunar valves. The reproductive secreting organs are compact and oblong, the efferent tubes communicating with the ureters and ending in a rudimentary organ in the cloaca; the claspers are present in the males, as appendages to the posterior edge of the anal fin, fissured toward the end, leading to a blind subcutaneous sac well lubricated with mucus and the secretion of a glandular body; the ovaria are comparatively small, and the ova are larger and fewer than in common fishes, and more as in birds; most of the genera are viviparous, but some of the genus raia are oviparous. The claspers are not mere organs of prehension; they may be so rotated as to bring an opening in them opposite to the spermatic duct, and may, according to Agassiz (" Proceedings of the Boston Society of Natural History," vol. vi., p. 377, May, 1858), be introduced into the oviducts, and reach the glands there situated for the formation of the egg case. They are true intromit-tent or copulatory organs.
The egg cases of the skate are often seen on our beaches after a storm; they are quadrangular, about two inches by one, brown and leathery, each corner prolonged into a tubular process; they look somewhat like pillow cases, and are often called sailors' purses and skates' barrows. The young within the egg has no investing membrane, and the yolk seems to bear no relation in size to that of the embryo; water for respiration is admitted and ejected through the corner prolongations, and the young fish escapes through a transverse fissure at one end. The horny egg case may be formed in each oviduct, and is surrounded by a glandular enlargement which secretes its materials; it is formed before the egg descends into it, in the shape of a pocket open above for the reception of the egg, which must be impregnated in the ovary, contrary to the usual order of things, in which the yolk is enclosed before the shell is formed; as the eggs are found to be of different sizes and various degrees of development in the ovary, it is probable that several years are required for their maturity; these peculiarities show the propriety of placing the skates (with the sharks forming the division of selachians of Aristotle and Agassiz) in a class by themselves.
The teeth of the rays are generally tubercular, in close quincunx order like a mosaic pavement. Disgusting as is the form of the rays, their flesh is esteemed a delicacy in England and France, though it is rarely eaten in America except by those of European origin; it is tough when first caught, but becomes tender by being kept several days; with us it is most commonly used as bait for lobster pots, or for manure. Of the families of rays, the pristidoe and torpedinidoe will be described under Sawfish and Torpedo respectively; the cephalopteridoe have been no ticed under Devil Fish. - The family rhinoba tidoe are intermediate between sharks and rays, having the form of body, position of fins, thick, fleshy tail, and smallness of pectorals of the former; the anterior part of the body forms a disk by the union of the pectoral fins with the snout, the latter divided from the former by a furrow, whence these have been called beaked rays; the first dorsal is over the ventrals; the caudal bilobed, with the upper lobe the larger, and the keel of the sides continued along it; margins of mouth generally undulated, three protuberances of the under jaw fitting into corresponding indentations in the upper; nostrils longitudinal near the mouth, with flaps. - In the family raiidoe or the typical rays, the snout is more or less pointed, the disk of the body and pectorals usually rhombic; tail slender, with two small dorsals near the end and sometimes a caudal; spiracles near the eyes; mouth curved, with the convexity forward; teeth of males with a central cusp in spawning time; skin either smooth or studded with prickles pointing backward, sometimes with spines on the dorsal ridge and sides of tail.
This family includes the genus raia (Cuv.), with about 30 species, embracing the best known in America and in Europe, and such as are commonly eaten in the latter. The smooth ray or common skate of the northern coast of America is the raia Ioevis (Mitch.); it is of a uniform light brownish color above, and dingy white below; the female is marked above with blackish spots; it attains a length of from 3 to 5 ft., and a weight of 200 lbs.; it is found from New York to the British provinces; the body is generally smooth, but there are small spines about the orbits, on the anterior edge of the pectorals, and on the tail; the snout is blunt, and the teeth in compact rows, six-sided and nearly smooth. Its flat form is peculiarly adapted for life on or near the bottom; the usual mode of progression is by a gentle undulating movement of the pectorals, intermediate between flying and swimming; when in pursuit of prey or escaping from its enemies, the motions are rapid. The young are produced twice a year, in spring and in autumn, deposited in thin, horny, nearly quadrangular cases. Its flesh is said by Mr. Perley to be extensively consumed, and the fleshy part of the pectorals to be beautifully white and delicate; it is usually dressed in long thin slips, rolled like ribbon.
On the coast of New England, Nova Scotia, and New Brunswick it is frequently taken by the cod fishers, being generally hooked by its pectorals; it is pulled up like a dead weight to near the surface, unless caught by the mouth or head, and struggles violently on being drawn out. It feeds on fish, crustaceans, and mollusks, and is very voracious; it digs up clams with its powerful spade-like snout, crushing them easily with its rolling flattened teeth. The skin is covered with an abundant tenacious slime. There are eight or nine species in European waters, some attaining a weight of 200 lbs. The sharp-nosed ray (B. oxyrhyncha, Linn.) attains a length of 6 ft.; this is the favorite species in the French markets. The common skate or ray (R. batis, Linn.) is a large species, with a granulated skin above; the color is brown above, cinereous below or grayish white with black specks. Several species are common in the London market, where the females are known as maids. - In the family trygonidoe or sting rays the tail is slender, often whiplike, naked or bearing one or more barbed spines; no caudal fin; pectorals large, uniting in front of the head; spiracles large and close behind the eyes; teeth small, transversely elliptical, and ridged; skin either smooth or prickly, out without prickles on the pectorals.
The American whip sting ray (pastinaca has-tata, De Kay) occurs on the coast of the middle states, in Long Island sound, and sometimes on the coast of Massachusetts; it is olive brown above, and white below; it attains a length of from 5 to 8 ft., including the tail. It is not uncommon on the shores of New Jersey, where it is caught both by hook and seine, varying in size from a breakfast plate to a width of 4 ft. and a tail of 5 ft.; the fishermen always cut off the tail at once, to prevent wounds from its spines, which, being serrated, produce extensive lacerations accompanied by severe inflammation. The principal use made of this species, and indeed of all the rays in this country, is to extract the oil from the liver, which, with that from this organ in sharks, is employed for various domestic and medicinal purposes. The European sting ray is common in the Mediterranean and on the southern Atlantic coast; it was well known to the ancients, who thought it capable of inflicting poisoned wounds; it twists its long tail around its prey or its enemies, causing very severe lacerated wounds; its flesh is not eatable.
The spines of some of the species of this genus are used by savages as arrow and spear heads. - In the family myliobatidoe or eagle rays, the head is more elevated than in the other families, projecting as far as the gills, without fin rays on its sides, but with a kind of cephalic fin in front of the skull making the point of the disk; the pectorals are very large and winglike; the tail is long and slender, with a small dorsal and strong spine; the mouth is transverse, with the dental plates reaching far back into the cavity of the mouth; the teeth are like a mosaic pavement, large and even, in several rows forming a convex surface; the eyes and spiracles are on the sides of the head, and a broad ridge runs between the two; the interrupted pectorals on the sides of the head are a family character. In the genus mylioba-tis (Cuv.) the nasal membrane is square, and the pectorals end in an angular projection; the teeth form long hexagonal plates in the middle, with two or three short or equal rows on the sides. The M. acuta (Ayres) is found on the Massachusetts coast and in Long Island sound, and attains a length of about 4 ft.; the body is smooth and reddish brown above, whitish below; tail very slender and armed with spines.
The eagle ray of the Mediterranean (M. aquila, Risso) grows large; the wounds made by its spines are much dreaded by fishermen. Several species are found in the seas of the warm parts of the globe. In rhi-noptera (Kuhl) the nasal membrane is notched; the central teeth are the largest, the three lateral rows growing smaller and smaller externally. In aëtobatis (Müll.) the nasal membrane is lobed, which would embrace many species of rhinoptera as usually defined, and the pectorals are rounded; the teeth form a single row of simple arched plates, without lateral rows. In zygobatis (Ag.) the nasal lobes and the pectorals are as in the preceding genus; the central rows of teeth are much the largest, the first lateral about half as large, and the two external very much smaller. In go-niobatis (Ag.) the palate is broadest behind, and the plates are obtusely angular, with their rounded edges forward. - There is hardly a family of fishes in the classification of which more confusion reigns than that of the rays; naturalists see them only in rare instances, and almost always single specimens at a time; there can be little doubt that the two sexes of the same species have in some instances been made into distinct species.
Even our most common rays are very imperfectly known, and the genus raia embraces many species which are not congeners. - For details on the embryology of the rays, see Prof. J. Wyman's paper in "Memoirs of the American Academy," vol. ix., 1867, and Mr. Putnam's in the "American Naturalist," vol. iii., 1870.
Smooth Skate (Raia laevis).
American Sting Ray (Pastinaca hastata), under surface.
Ray, a N. W. county of Missouri, bordered S. by the Missouri river; area, about 570 sq. m.; pop. in 1870, 18,700, of whom 1,833 were colored. It has an undulating surface, covered with forests and prairies, and a generally fertile soil. It is intersected by the St. Louis, Kansas City, and Northern railroad. The chief productions in 1870 were 187,736 bushels of wheat, 1,245,233 of Indian corn, 177,461 of oats, 39,114 of potatoes, 6,610 tons of hay, 190,355 lbs. of tobacco, 42,374 of wool, 122,774 of butter, and 11,085 gallons of sorghum molasses. There were 9,009 horses, 2,155 mules and asses, 5,469 milch cows, 11,176 other cattle, 20,580 sheep, and 38,523 swine; 2 flour mills, and 13 saw mills. Capital, Richmond.