Horton Mountains to Truro. There was then no strait at all. The Basin opened broadly into the Bay of Fundy. Cobequid Bay was much wider than at present, and penetrated eastward beyond Truro. One of the Acadian provinces, Prince Edward Island, was wanting.

Within the whole bay thick beds of red sand were deposited, and similar strata were at the same time accumulating in the Gulf of St. Lawrence, off the northern coast of Nova Scotia, and especially over the area now occupied by Prince Edward Island. These beds now form a coarse friable red sandstone which is almost entirely barren of fossils, for it had afforded only a few reptilian remains in Prince Edward Island. Acadia must at that time have been peopled with animals, and covered with vegetation; but the conditions for the preservation of the remains of either were very unfavorable. The bay was then open to the full sweep of the tide, which may at that time have acted with even much greater force in the region of the Basin of Minas than at present, because the tidal wave, not being obliged to pass, as at present, through the narrow Strait of Minas, would have had an opportunity of exercising its full force, rising higher and higher as it rushed up the ever-narrowing head of the bay, but it may have been that at that time the isthmus which unites the peninsula of Nova Scotia with the main land was submerged, in which case the extraordinary tidal phenomena of the Bay of Fundy could not have resulted. The sandstone beds show, in their oblique lamination, the action of strong and shifting currents. There was not the same opportunity presented for the preservation of such footprints as may have been left on these sands, as existed in the quiet estuary of the Connecticut, or the present Basin of Minas. At intervals during the deposit

of the Connecticut River beds, there were volcanic disturbances, attended by the formation of dykes, and the spreading out over the beds of thick masses of lava. The New-Red Sandstone period was attended in Nova Scotia by similar phenomena. Just after the formation of the sandstone beds in the Basin of Minas and Bay of Fundy, submarine volcanic action broke out along the line of the present North Mountains, and immense quantities of melted matter were thrown up from beneath, and spread over the New-Red Sandstone strata, either in liquid, molten streams, or a volcanic ash. This ancient lava is called trap. The volcanic disturbance went on for some time, until these beds had acquired a great thickness. Similar eruptions took place at the same time at the Two, Five, and Partridge Islands, Capes d'Or and Sharpe, and at the Isle Haute. It is very probable that all these now isolated trap masses may have been at that time continuous.

The land was then elevated so as to bring all their beds • in the Basin of Minas, and along the shores of the Bay of Fundy above water, and as the red sandstone beds had a slight dip to the northward along the southern coast, the volcanic beds had a like dip towards and under the bay. The trap beds were very thin inland, but became thicker towards the shore. Running water began its work on the southern edge of the trap deposit, along the present line of the valley between the North and South Mountains, and with the assistance of glacial action and the sea, which afterward flowed through it, excavated that depression. To the north, the waves, beating along the whole bay coast for centuries, cut away the trap-beds, so that we have now only a narrow strip left, the North Mountains from Blomidon to Briar Island. At the time of the elevation of the New-Red Sandstone beds, the Basin of

Minas, as well as a large portion of the Bay of Fundy, was occupied with them; but they have since been largely removed, except where overlaid by trap deposits, or otherwise protected, and only small remnants are now left fringing the shores of Nova Scotia and New Brunswick. Prince Edward Island made its appearance with the rise of the land, and it must at first have been of much greater extent than at present, perhaps even having been united to Nova Scotia.

a, Silurian strata. b, Carboniferous sandstone and shales. c, c, c, c, c, Triassic red sandstone. d, Trap overlaying red sandstone.

The reptiles and birds of the New-Red Sandstone period have passed away, and the earth is peopled by a new creation. In that period the world had reached that stage in its development when it was fitted for the rule of the brute force of giant reptiles. To-day mind rules. God's other creations signed their mark on the pages of geological history.

NOTE. The above diagram is an ideal vertical section across the country from Wolfville to Parrsboro', intended to show the relative position of the beds of rock of which it is composed. The hills south of Wolfville consist of beds of sandstone and shale, b, belonging to the lower part of the Carboniferous formation. These beds are inclined to the north, and they rest on the upturned edges of beds of slate, a, of Lower Silurian age. Carboniferous beds, b, appear at Parrsboro', but they are much newer than those near Wolfville. In the trough-shaped depression in these Carboniferous strata, the ancient Basin of Minas, lie the thick beds of the New-Red Sandstone, e, e, e, e, which, except where they are protected by the overlying masses of trap, d, d, at Blomidon and Partridge Island, are worn away into low hills, or cut through by the river or the water of the Strait. The horizontal line represents the sea-level. This section is based on one by Dr. Dawson, in his "Acadian Geology," with additions by the writer.

244

SOMETHING ABOUT JELLY-FISHES.

BY EDWARD S. MORSE.
PLATE 8.

THE loiterer by the sea-side may have noticed in his rambles on the beach, certain gelatinous substances left by the retreating tide. An interest excited by so strange a sight may have prompted a closer examination, and yet recognizing nothing tangible or definite in the structure of these shapeless bodies, a desire has been really awakened to know something about them. We will try to satisfy this curiosity, by giving a brief account of a few of our more common Jelly-fishes; for these shapeless lumps of jelly, seen stranded on our beaches, are really animals, assuming the most graceful and symmetrical forms in the water.

The Jelly-fishes, or Medusa, have long excited the attention of naturalists from their singular structure, and the wonderful changes occurring during their growth.

While in the higher expressions of animal life the anatomist may puzzle over the intricacies of a complicated organization in the Jelly-fishes, he is at first more perplexed to find anything like organization in their parts, though they are really highly organized compared with animals still lower in the scale. So transparent are some, that one can hardly detect their presence in the water, and so largely does the sea-water enter into their composition, that certain kinds when dried lose ninety-nine one hundredths of their own weight.

Péron and Lesueur, two distinguished French naturalists, who, in the early part of this century made a voyage around the globe, thus summed up the results of their combined observations on these animals. "The substance

of a Medusa is wholly resolved, by a kind of instantaneous fusion, into a fluid analogous to sea-water; and yet the most important functions of life are effected in bodies that seem to be nothing more, as it were, than coagulated water. The multiplication of these animals is prodigious, and we know nothing certain respecting their mode of generation. They may acquire dimensions of many feet in diameter, and weigh, occasionally, from fifty to sixty pounds; and their system of nutrition escapes us. They execute the most rapid and continued motions; and the details of their muscular system are unknown.

"Their secretions seem to be extremely abundant; but we perceive nothing satisfactory as to their origin. They have a kind of very active respiration; its real seat is a mystery. They seem extremely feeble, but fishes of large size are daily their prey. One would imagine their stomachs incapable of any kind of action on these latter animals in a few moments they are digested. Many of them contain internally considerable quantities of air, but whether they imbibe it from the atmosphere, extract it from the ocean, or secrete it from within their bodies, we are equally ignorant. A great number of these Medus are phosphorescent, and glare amidst the gloom of night like globes of fire; yet the nature, the principle, and the agents of this wonderful property remain to be discovered. Some sting and inflame the hand that touches them; but the cause of this power is equally unknown."

Professor Richard Owen quotes these "lively paradoxes" to show the progress made since then in clearing up many points that were obscure at their time, and to show that even the skilful naturalist, with abundant material at hand, may plod on with uncertainty unless aided by the higher powers of the microscope. Recent works published by