REVIEWS. 
189 
mixed xvitli Tertiary strata, "but their presence cannot modify the age of the 
new land formations. This admission would be against reason quite as 
much as the assertion that we are now still living in Cretaceous times, 
because animals of Cretaceous type are dredged from the depths of the 
ocean.” 
With this extract we may conclude our notice of Professor Lesquereux’s 
work, the value of which is enormously enhanced by the beautiful plates 
which illustrate it. These are 64 in number, and contain excellent figures 
of every species referred to in the text — a condition, indeed, which is abso- 
lutely essential to every descriptive book on fossil botany. 
Next to Professor Lesquereux’s Tertiary flora, the most important contri- 
bution that we have received from the Survey is the first part of the fourth 
volume of its Bulletin,* which contains no fewer than 14 articles, most of 
them of considerable interest. The majority are of zoological nature. Thus 
we have an interesting account of the birds of the Lower Rio Grande of 
Texas by Mr. G. B. Sennett, edited by Dr. Elliot Coues, devoted especially 
to a description of the habits and manners of the birds observed by the 
author, but including also many valuable notes on their characters by the 
editor. A new species of Tit is described under the name of Farida nigri- 
loba, Coues. Another important ornithological paper is that by Mr. Ridgway 
on the American Herodiones, of which the first part here appears, contain- 
ing a synopsis of the American genera of Ardeidse and Ciconiidse, with a 
monograph of the American species of the genus Ardea. The American 
forms of the group Herodiones are referred by the author to five families, the 
Cancromidae (Boatbills), Ardeidae (true Herons), Ciconiidae (Storks), Ibididae 
(Ibises), and Plataleidae (Spoonbills). The Eurypygidae or Sun-Bitterns, 
which are also an American group, are placed by some authors near the 
Rails, but Mr. Ridgway seems to think that they may nevertheless be Hero- 
diones, although he does not include them in his synopsis. The monograph 
of the species of Ardea contains descriptions of four species, three exclu- 
sively American, and the fourth our Common Heron, which is said to occur 
occasionally in Greenland. Two new genera of herons ( Dichromanassa and 
Syrigma) are proposed. The two American Storks, according to Mr. Ridg- 
way, present a rather difficult question of synonymy, which we may recom- 
mend to the attention of our ornithological readers; for one of them the 
author has established the new genus Euxenura , characterized especially by 
peculiarities of the tail, and the remarkable development of the lower tail- 
coverts. 
From birds we may pass to Mammals, under which head we have a series 
of notes, by Dr. McChesney, on the animals of that class observed by him 
at Fort Sisseten in Dakota, of which those relating to the Rodents are the 
most important. Dr. McChesney bears testimony to the recent disappearance 
of the larger Mammals under the pressure of advancing civilization. The 
most interesting communications on Mammalia, however, are two notes by 
Dr. Coues, on consolidation of the hoofs in the Virginian deer, and on a 
* “ Bulletin of the United States Geological and Geographical Survey of 
the Territories.” Vol. IV., No. 1. 8vo. Washington : Government Print- 
ing Office. 1878. 
