156 The American . 



[Fel: 



As a purely anatomical work it is excellent. It will be much more 

 useful to veterinarians than to any other class of readers and it was 

 largely written for them. However, no one in any way interested in 

 the anatomy of the dog can afford to be without it ; and it is gratify- 

 ing to have the labor performed for the first time so faithfully and so 

 well. An English translation should be made. — Moritz Fisrini;. 



Olenn-a! Notes. 



GEOLOGY AND PALEONTOLOGY. 



The Crystalline Cambrian Deposits in Massachusetts. 

 The Essex Bull, vol. xxiii, 1891, publishes another paper by Mr. J. H. 

 Sears, on the Olenellus Cambrian rocks of Essex County, Mass. The 

 numerous out-crops of these rocks, their position and condition lead 

 the author to the following theory : 



That during the Cambrian period a vast sheet of these sediments 

 was deposited over the entire region to the depth of some hundreds of 

 feet. They have been distorted and crumpled into anticlinal and syn- 

 clinal folds by the intrusion of eruptive rocks. The distortion left 

 their entire surface a series of cracks and faults, which made them a 

 prey to the forces of erosion and decay. The ice sheet during the 

 glacial period scoured these sedimentary beds and ground the rocks to 

 boulders and fine till, which is now scattered over Cape Ann and 

 in the neighboring waters of the Atlantic Ocean. This would account 

 for the absence of glacial grooves on the surface of granite areas, for 

 the ice sheet probably never touched the greater portion of the granite 

 area. Aerial decay has since destroyed all that was left of the sedi. 

 mentary beds after the ice period, except such remnants as are found 

 to-day. The absence of fossils in many of the beds is due to contact 

 metamorphism. 



The Fauna of the Armorician Sandstones.— M. Charles 

 Barrois has recently published {Ann. Soc. Geol. du Nord. Avril, 1891) a 

 memoir in which hedescril.es the fauna, and discuses the systematic 

 position of the Armorician sandstones of Bretagne. The fauna con- 

 sists of 151 sponges, 155 Brachiopods, 157 Lamellibranchs, 212 (Jas- 

 tropods, 218 Pteropods, and 219 Crustaceans. In giving the biologi- 

 cal characters of the fauna, the writer calls attention to the verv slight 



