mals, birds, or reptiles; but when comparative anatomy became better understood, it was perceived that their relations to mammals and birds were only in external forms, while the essential features of their structure were undeniably reptilian. Every one has heard of flying dragons, reptiles which, like "flying fishes" and "flying squirrels," are able partially to sustain themselves in the air by means of parachute-like expansions from their bodies. But in the Pterodactyls were true aerial reptiles, as bats are genuine flying mammals (see Fig. 72). The Pterodactyl, in the length of its neck and form of its head, resembled a bird. The trunk and tail were like those of a quadruped. The numerous conical recurved teeth were formed after the Saurian type. The anterior extremities were constructed after the character of bats, the last finger having been greatly elongated, and adapted for supporting a membranous wing, the impression of which is sometimes preserved in connection with the bones. We know twenty species of this remarkable order, all Old-World marvels save a single pair of long finger-bones found at Phoenixville in Pennsylvania. Some were no larger than a snipe, while others were capable of expanding their wings to a breadth of sixteen feet.

Along the valley of the Connecticut River, from the neighborhood of New Haven to the northern part of Massachusetts, is a brownish-red sandstone, resting mostly in horizontal beds, which have been extensively quarried for building purposes. On the banks of the river at Portland, opposite Middletown, are excavations several acres in extent, which have been in progress more than a hundred years. Thousands of ship-loads have been sent down the Connecticut, and built into the aristocratic brown stone fronts of New York. This formation furnished a valuable resource to the earliest settlers of Connecticut. Their