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r Monthly Microscopical 
L Journal, May 1, 186^. 
NEW BOOKS, WITH SHORT NOTICES. 
A History of the British Hydroid Zoophytes. Bj Thomas Hincks, B.A. 
in 2 vols. London : Van Voorst, 1868. — Mr. Hincks is so well 
known as an able and indefatigable explorer of the Hydroid Coelen- 
terates, that we naturally anticipated that his treatise on the British 
Hydroid Zoophytes would be a very complete and valuable mono- 
graph. Let us say, then, in the first place, that we have by no 
means been disappointed. The work which Mr. Van Voorst has 
just issued fills a void which existed too long in our literature, 
and in our opinion takes the place which was once occupied by 
Johnston's ' History of the British Zoophytes.' Of course Mr. 
Hincks has drawn largely on the results of his own inquiries in 
preparing this treatise ; but he has not on that account neglected 
the valuable researches of Allman, Busk, Strethill Wright, Alder, 
Sars, and Van Beneden. Of the two volumes, the first embraces 
the text, and is divided into the general remarks on the group and 
the descriptive portion ; the second includes the Plates, which 
have been executed by Mr. Tuffen West. Those who have paid 
any attention to the study of the Coelenterata are aware how ex- 
tensive is the terminology applied to the class Hydrozoa; and 
though Professor Greene has simplified the whole as much as pos- 
sible in his excellent manual, it is nevertheless tough work for the 
beginner to master. Eeaders will therefore be very glad to learn 
that Mr. Hincks has considerably reduced the list of technical 
terms, and has employed only those which are essential to the 
recognition of species. Indeed, he confines himself to twenty-one 
terms, all of which are briefly and clearly defined. In most cases 
these are similar in significance to the expressions employed by 
Huxley and Allman ; but the term Gonophore is used in a more 
definite sense than that in which the latter uses it. As Mr. 
Hincks remarks, "As employed by Allman, the gonophore is 
sometimes the reproductive bud ivith its ectotheca, and sometimes it 
contained zooid, whether fixed or free. To me the gonophore is 
the whole bud ; and the sexual zooid developed in it, whether as 
a fixed sac or a floating polypite, is the gonozooid." Having 
explained his terminology, the author then proceeds to deal with 
the anatomy and physiology of the group. This he does in an 
introductory chapter of more than forty pages, illustrated by 
numerous woodcuts intercalated in the text. Eate of growth, 
Phosphorescence, geographical distribution, methods of collecting, 
are points also treated on in this chapter. Not the least interesting 
of the author's remarks are those on the subject of development, 
in which he traces the phases of ovum and planiiJa. 
The method of classification is simple and convenient, as it is 
based on rather broad characters, and is upon the dichotomous 
scheme. The whole of the order is divided into two sections: 
