BALA LIMESTONE, one of the most interesting of the Calcareous Deposits which have been examined by Professor Sedgwick in the midst of the Schistose Rocks of North Wales. There are two bands of this rock, exhibited on the west of the Berwyn Mountains and on the east of Bala Lake. Two miles north-east of Bala the limestone mid the schistose rocks In which it lies may be well seen, fuid numerous fossils may be gathered at this and at many other points in the vicinity of Bala, on both aides of the lake. Professor Sedgwick has satisfied geologists of the true position of these tracks with refer ence to the slates of the Berwyn range, and the flags and slates of Llangollen. The series is in two parts, thus :— Upper Part. Flags and schistose beds of Llangollen, with upper Silurian fossils.
Lower Part. Schistose beds with limestone bands, the lowest of which occur at Bala, and yield lower Silurian fossils.
This is the view of l'rofessor Sedgwick, and the Bala and Llandeilo limestones are thus nearly coeveL BALiE'NA (from the Greek iniAcuva), the Latin name of the Coin mon or Greenland Whale, and adopted by naturalists as a generic term, to comprehend all the other species which agree with it in their zoological characters. [Creace.m]
BALiENO'PTERA. This term waft, invented by Lac6pi‘de, to denote those whales which are distinguished by having an adipose fin on the back, whence they are called Fitment by sailors, and which he proposed to separate from the other Behtsur for the purpose of form ing them into a distinct genus. The character however upon which he proposed to make this separation is utterly void of importance, and exercises no assignable influence upon the habits and economy of animal life. His division is consequently vicious, and cannot be admitted into a natural or philosophical system of mammalogy, at least for any other purpose than as a matter of simple convenience. The word itself is compounded of the terms balama, n whale, and Irripov, a wing or fin.