228 The Ottawa Naturalist. 



The definitions of the orders and the families of the Trilo- 

 bita given by Dr. Beecher in article XVIII, point to the recent 

 rapid advances made in palaeobiologic studies ; and whilst re- 

 taining the families adopted by Barrande, Salter and Zittel, the 

 order of arrangement, consequent upon his own researches, is 

 very different. There are certain families and genera of trilobites 

 which Dr. Beecher has not yet included in his classifications. 

 These it were well to keep in mind and obtain information 

 thereon so as to enable them to be placed in their proper posi- 

 tion in the classification. To Dr. Beecher and Mr. H. M. Bernard 

 we owe much regarding the affinities and structure of a trilo- 

 bite.— H. M. A. 



Beecher, ChaS. E. — On the occurrence of Silurian strata in 

 the Big Horn Mts., Wjoniing, and in the Black Hills, South 

 Dakota, (not previously noted). Amer. GeoL, Vol. XVIII, 

 pp. 31-33, Minneapolis, July, 1896. 



Dr. Beecher notes the occurrence near Buffalo, Wyoming, 

 o{ Haly sites catenulatus, L., Heliolites interstinctus, L., species of 

 Zaphrentis, Favosites and Amplexus, besides a Rhynchotrema 

 allied to R. increbescens and a small Scenidium or Or this which 

 may be from a horizon as yet indeterminate between the limits 

 limits of the Trenton and Niagara. He further records the 

 occurrence of Endoceras annulatum of Maclurea Logani, and of 

 Halysites from a locality a few miles south-east of Deadwood, 

 S. Dakota. " Recent investigations have shown," says the 

 writer, " the unreliability of several species generally considered 

 as characteristic of the American Niagara, notwithstanding that 

 in Europe the same forms are well-known to have a wide 

 vertical range." — H. M. A. 



Crosby, W. O. — Englacial Diift. Technology Quarterly, Vol- 

 IX, Nos. 2 and 3, pp. 1 16-144, June and September, Boston* 

 1896. 



Crosby, W. O.— Contribution to the 'Geology of Newport neck 

 and Conancut, Island. Amer. Jour. Sc., Vol. Ill, pp. 230- 

 236, March, New Haven, 1897. 



