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high up the Little Blackfoot River, but did not succeed in killing one.

SHELDRAKE (Mergus Americanus). I shot a female bird of this species at the highest camp on the Little Blackfoot River, near where it doubtless had raised a brood, as they seek such clear rapid streams for that purpose in the Cascade Mountains. M. serrator, the female of which is so much like this, has probably never been obtained far from the coast.

WESTERN GREBE (Podiceps occidentalis). I found this Grebe on the Alkaline lakes of the Columbia Plain, October 8th, about the same time of year that I obtained the first known specimen from near Walla Walla, in 1853. Its breeding place may be on the shores of these lakes.--To be concluded.



(Continued from Vol. I, page 30.) WHILE grim and monstrous Dinosaurs ranged the forests and flats of the coast of the Cretaceous sea, and myriads of Gavials basked on the bars and hugged the shores, other races peopled the waters. The gigantic Mosasaurus, the longest of known reptiles, had few rivals in the ocean. These Pythonomorphs were the sea-serpents of that age, and their snaky forms and gaping jaws rest on better evidence than he of Nabant can yet produce.

Ten species of this group are known from the Cretaceous beds of the United States, of which six have been found in New Jersey. Two others occur in Europe. In relative abundance of individuals, as well as of species, New Jersey is much in advance of any other part of the world where excavations have been made.

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These creatures have been referred to the neighborhood of the Varanidæ or Lace-lizards, which now baunt the shores of rivers in the tropics and southern regions of the Old World. Cuvier, Owen and others, have expressed this view, and there has been little dissent from it expressed by palæontologists. They readily constitute, however, a distinct order of reptiles, combining features of serpents, lizards, and Plesiosaurians. This is readily understood by the light of the abundant material discovered in various parts of the United States. The lizard-like affinities are, it is true, to the Varanians rather than to any others.

The Mosasaurus was a long slender reptile, with a pair of powerful paddles in front, a moderately long neck and flat pointed head. The very long tail was flat and deep, like that of a great eel, forming a powerful propeller. The arches of the vertebral column interlocked more extensively than in other reptiles except the snakes, presenting in a prolongation of the front of one, which enters beneath that immediately in advance of it, a rudiment of that extra articulation called the "zygosphenal.” In the related genus Clidastes, this structure is as fully developed as in the serpents, so that we can picture to ourselves its well known consequences: their rapid progress through the water by lateral undulations; their lithe motions on land; the rapid stroke; the ready coil; or the elevation of the head and vertebral column, literally a living pillar towering above waves or brush of the shore swamps. While the construction of the skull was as light as that of the serpents, it was, apparently, not so strong. The sutures are more frequently of the squamosal type, and the brain case was not as fully ossified in front. The teeth, too, are less acute, and therefore less adapted for retaining struggling prey. While the jaws were longer, the gape was not so extensive as in serpents of the higher groups, for the os quadratum, the suspensor of the lower jaw, though equally movable and fastened to widely spread supports, was much shorter than in

them. But there was a remarkable arrangement to obviate any inconvenience arising from these points. While the branches of the under jaw had no sutural connection, and possessed independent motion, as in all serpents, they had the additional peculiarity, not known elsewhere among vertebrates (except in a few snakes), of a movable articulation a little behind the middle of each. Its direction being oblique, the flexure was outwards and a little downwards, greatly expanding the width of the space between them, and allowing their tips to close a little. A loose flexible pouchlike throat would then receive the entire prey, swallowed between the branches of the jaw; the necessity of holding it long in the teeth, or of passing it between the short quadrate bones would not exist. Of course the glottis and tongue would be forwards. The physiognomy of the reptile, with apparently dislocated jaws and swollen throat, as he passed a Chimæra to his internal laboratory, could scarcely be prepossessing.

The Clidastes and Macrosaurus were the more slender of these heteroclite beings, while Mosasaurus embraces the most gigantic. The Clidastes iguanavus could not have been shorter than thirty feet, and presented a reduction of the length of the paddles, consistent with its thoroughly serpentlike vertebral column. Macrosaurus validus considerably exceeded this length. Mosasaurus Mitchellii and M. Missuriensis propelled sixty feet of length through the waves, while no portion of these have been found to equal the M. maximus, which have recently been exhumed.

The reptilian whales of those troublous times, were the Cimoliasaurs and Elasmosaurs. These were the Plesiosaurs of Cretaceous life, and probably had a great range over the earth, Portions of them have been found in England and North America to our far western regions. Cimoliasaurus appears to have resembled Plesiosaurus in general, while Elasmosaurus added to its type an enormous and flattened tail, relatively as long as that of the Mosasaur, or the modern

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