504 - THE AMERICAN NATURALIST. . (Vor. XXXIX. 
siderable attention is also paid to the field identification of the 
several species. The distinguishing marks of our two cormorants, 
for instance, are pointed out, and other birds usually puzzling to the 
mere observer are shown to be identifiable in the field with the use 
of due care. 
It would be unfair to convey the impression that the book is 
solely a record of personal experience or that the observations have 
been confined to Ipswich and its immediate neighborhood. As a 
matter of fact the author is well acquainted with the County as a 
whole, and he has made the fullest use of the observations of others, 
both published and unpublished, consulting the literature and exam- 
ining collections. Nevertheless, the book remains to an unusual 
degree a personal achievement, upon which Dr. Townsend is to be 
heartily congratulated. The book is written in a direct, forcible 
style, with an abundant enthusiasm which is tempered by an emi- 
nently scientific attitude of mind and a discriminating sense of 
humor. It makes excellent reading even when read consecutively, 
and after perusal it should take its place on the ornithologist's 
shelves alongside of Major Bendire's Zife Histories. 
he volume is excellently printed on good paper and hasa bibli- 
ography, a full index, a view of a typical sand dune with adjoining 
beach, and a map of the County. 
F.H. A, 
Notes.— The finer structure of the heart of the higher crustaceans 
has been worked out by Gadzikiewicz (Jena. Zeitschr., Bd. 39, p. 203) 
with the following results. The heart proper consists of two layers: 
an inner muscular and an outer adventitia ; no endocardium is present. 
The histological characteristics of these two layers are described in 
detail for many crustaceans. 

A systematic account of the anatomy of 'Haliotis has just been 
published by H. J. Fleure (Jena. Zeitschr., Bd. 39 p. 245). The 
author believes that Pleurotomaria and Haliotis are near relatives but 
are not derived one from the other. They are probably early deriva- 
tives from the common prosobranchian stem but not so early as the 
Docoglossz and Fissurella. 
The histology of the tunicate blood vessels has been investigated 
by Fernandez (Jena. Zeitschr., Bd. 39, p. 325), who concludes that 
the blood system in these animals consists of two parts: the propel- 
ling part composed of the infolded pericardial wall or heart proper, 
and the transmitting part made up of the walls of the blood vessels 
and the inner connective-tissue layer of the heart. 
