134 JReview of the Controversy Regarding the Motion of Glaciers. 



surface than on each side, and about one fourth wider transversely 

 than the dor.-;o-ventral diameter ; each inner vohition slightly impress- 

 ing the inner side of the succeeding turn. Umbilicus a little more 

 than half the dorso-ventral diameter of the outer volution, and showing 

 all the inner turns. Spire apparently scarcely (or perhaps not) rising 

 above the upper surface of the last turn. Septa rather distinctly concave 

 on the side facing the aperture ; separated on the outer side of the whorls 

 (at a point where the dorso-lateral diameter is about 1.25 inches) by 

 spaces measuring 0.35 inch ; all showing a very slight backward curve 

 on the broadly rounded periphery, and passing nearly straight across 

 each side. Surface, siphuncle and non-septate part of the shell not 

 certainly known. 



Greatest breadth of the typical specimen (which is septate) to the 

 broken outer extremity 5 inches; height or thickness of same about 

 2.50 inches. Dorso-ventral diameter of the volutions increasing about 

 three fold each turn. 



The locality given for this species in the Ohio Paleontology is the 

 upper part of the Cincinnati Group, at Eichmond, Indiana, and in 

 Warren and Clinton counties, Ohio, but I have never heard of any 

 other specimen than the single one found somewhere about Eichmond, 

 Indiana. 



Review of the Present State of the Controversy Concerning the Motion 

 of Glaciers. By Peof. E. W. Claypole, B.A., B.S., of Antioch 

 College, Yellow Springs, Ohio. 



In the fii-st part of this paper published in January last, a short sketch 

 was given of various theories that have been at different times put 

 forward to account for the motion of a glacier. In all of them the 

 ice was supposed to move as ice, and the efforts of their authors were 

 directed to the discovery of some source of power existing in the 

 glacier, or acting on it, from without, that would be sufficient to pro- 

 duce the movement observed. 



De Saussure, Eendu and Forbes thought they had found this in 

 the weight of the ice — that is, in gravitation. De Charpentier and 

 Moseley on the other hand, brought in the additional agency of heat. 

 The demonstration of the high unit of shear possessed by ice refuted 

 the theory of Eendu and Forbes, or rendered necessary some great 

 modifications ; DeSaussure's hypothesis was untenable on mechanical 

 grounds, and the discovery by Aggasiz of the almost imvarying tern- 



