340 Letters, Announcements, ^t. 



watershed. The picture thus suggested presents a chain of 

 islands in Tertiary times in place of the continuous isthmus now 

 existing. Zoology enables us to discern but faintly the old 

 islands that appear once to have existed in this region. These 

 observations of Dr. Maack's, giving them greater definition, 

 will doubtless enable us to read the history of the present 

 geographical distribution of the birds of the isthmus with far 

 greater precision. 



Our valued contributor Dr. Coues is about to publish a 

 * Key to North-American Birds.' The prospectus states that 

 the work will consist of about 300 octavo pages, and will be 

 illustrated by six steel plates and upwards of 250 woodcuts. 

 Its object is to furnish a manual of the birds of North America, 

 in which will be expounded the latest views in ornithology. 

 The introductory part will give a general account of the anatomy 

 and classification of birds, and full explanations of all the terms 

 used in ornithology. A key to the genera and subgenera will 

 follow, in the form of a continuous artificial table, while a 

 synopsis of living and fossil birds will contain concise descrip- 

 tions of every North-American species known to this time, with 

 characters of the higher groups and remarks relating to forms 

 not found in North America. 



Since our last issue, ornithologists have lost two of their most 

 zealous colleagues, both of them having worked through a long 

 series of years up to within a short period of their deaths. 

 Another veteran ornithologist has also passed away whose name 

 is familiar to all working at Indian Birds. 



The loss sustained by the death of Mr. George Egbert Gray 

 can only be partly estimated by viewing retrospectively the 

 mass of work he accomplished during the forty-one years he 

 remained in charge of the ornithological collections in the 

 British Museum. Mr. Gray contributed greatly to Griffith's 

 enlarged edition of Cuvier's ' Regne Animal,' and also published 

 several works on entomological subjects, including an illustrated 

 catalogue of the genus Pajnlio. In ornithology, Mr. Gray's 

 first work was the ' List of the Genera of Birds,' which was pri- 



