Proceedings of the Academy of Natural Sciences of Philadelphia, Band 13

Cover
Academy of Natural Sciences of Philadelphia, 1862
"Publications of the Academy of Natural Sciences of Philadelphia": v. 53, 1901, p. 788-794.
 

Was andere dazu sagen - Rezension schreiben

Es wurden keine Rezensionen gefunden.

Andere Ausgaben - Alle anzeigen

Häufige Begriffe und Wortgruppen

Beliebte Passagen

Seite 477 - Descriptions of new Lower Silurian (Primordial), Jurassic, Cretaceous, and Tertiary fossils, collected in Nebraska, by the exploring expedition under the command of Capt Wm. F. Raynolds, US Top. Engrs.; with some remarks on the rocks from which they were obtained; Acad.
Seite 367 - Shell transversely oval, or subtrigonal, moderately convex, rather thin; anterior side narrowly rounded ; base forming a regular semielliptical curve ; posterior side slightly truncated at the immediate extremity, abruptly rounded or subangular at its connection with the base below ; dorsal outline sloping from the beaks in front and behind, at an angle of about 120...
Seite 489 - Towards the base it consists of sandy clays, but a? we ascend to the higher beds, we find the arenaceous matter increasing, so that at some places the whole passes into a sandstone. It is not separated by any strongly defined line of demarcation from the formation below, the change from the fine clays of the latter to the more sundy material above, being usually very gradual.
Seite 195 - Arqiiatella, a peculiar form, was characterized. But while in other groups, particularly among the smaller land birds, the divisions have been minute and greatly extended, there seems to have been a general reluctance on the part of ornithologists with regard to recognizing these divisions. It may be that in this group Nature allows more external variation in forms very closely allied than is usual ; but until this is proved to be the case, it seems necessary, to keep pace with the progress of ornithology,...
Seite 310 - ... inches in length, measured from the tip of the lower jaw to the end of the longest lobe of the tail...
Seite 34 - Description of new species of Cretaceous fossils from New Jersey, Alabama, and Mississippi: Acad.
Seite 279 - The pertinacity with which they cling to certain feeding grounds, even when much molested, I saw strikingly illustrated on one occasion. The tide was rising and about to flood a muddy flat, of perhaps an acre in extent, where their favorite snails were in great quantities. Although six or eight gunners were stationed upon the spot, and kept up a continual round of firing upon the poor birds, they continued to fly distractedly about over our heads, notwithstanding the numbers that every moment fell.
Seite 496 - As the WIND RIVER DEPOSITS have not yet been seen in contact with any well marked beds of the other Tertiary formations of this region, and few fossils have yet been found in them, their position in the series remains doubtful. It is therefore only provisionally that we have placed this formation between the Fort Union and White River Groups in the foregoing section. It may possibly belong to the horizon of one of these rocks, or oven represent them both in part, or, what is more probable, it may...
Seite 472 - Although we still retain this as a distinct rock, our present impression is, that it is probably only a subdivision or member of the Fort Benton Group. Still, until more fossils can be obtained from it in the region of the typical localities, the question whether or not it should rank as a distinct formation must remain an open onr. That it is at least as old as the Fort Benton Group...

Bibliografische Informationen