1917] Book Reviews 161 
antennze in this species. The size of lurida in our series of twenty- 
four specimens varies in length from 4.35 mm. to 5.8 mm. It is 
impossible to separate the smaller specimens of lurida from ob- 
scura Parsh., by the inadequate and obscure description nor by the 
characters used in the key to the genus in his second paper. In 
both of these papers a great deal of emphasis is placed on size, 
narrow form, and antennal structures that apply equally well to 
the smaller specimens of lwrida. Possibly an examination of the 
types may enable one to separate them. 
BOOK REVIEWS. 
THe Mosquirors oF NortH AND CENTRAL AMERICA AND THE 
West Inpies. By L. O. Howard, H. G. Dyar and Frederick 
Knab. 
Volume 1, pp. I-VI, 1—520, 1912. 
Volume 2, pp. I-X, Plates 1-150, 1912. 
Volume 3, pp. I-VI, 1-523, 1915. 
Volume 4, pp. 525-1064, 1917. 
A notable chapter in that branch of Dipterology known as 
Culicology has been completed by the appearance of Volume 4 of 
this magnificent contribution to the knowledge of American mos- 
quitoes—a work which reflects high credit not only upon the 
authors and the institution which made publication possible, but 
also upon the recognition entomology has won and which really 
has made possible the completion of such a comprehensive and 
exhaustive study. It is a response to the recognition of the vital 
relation certain species of mosquitoes sustain to the welfare of the 
human race, and a demonstration of the fact that the knowledge 
of pathogenic forms is incomplete without a study of associated 
and allied species. 
The older entomologists easily recall the earlier days when only 
a few supposedly uninteresting and assumedly similar or very 
similar species of mosquitoes were known to occur in America, 
and can compare the conditions then and those obtaining now with 
practically 400 recognized species referable to 25 genera, and pre- 
senting undreamed of biological and morphological diversities — 
