616 REVIEWS. 
Tue Craw Frsu or NORTH AMERICA.* — The Cambridge Museum has 
issued another of its sumptuously illustrated and printed catalogues, 
which Res liberality of the State of Massachusetts has given it the means 
to do. From the hands of Dr. Hagen we have, as might be expected 
from his known care and accuracy in research, a monograph of much in- 
terest and value. The craw fish have been much neglected by naturalists 
in this eue though these ua tane lobsters have already made their 
mark in the local histories of the times, by the injury they occasionally do 
by ik ating our river dams, and Deine #3 the levee of A Missis- 
sippi near New Orleans, and the rice fields of the Southern stat 
As the author refers very briefly to their: burrowing habits, esa allud- 
ing to the fact that a species ‘severely damages the rice fields of the 
accordi vspaper ac 
counts they have by tunnelling the artificial banks o T Aeee e 
caused devastating floods; and while in Northern Maine we were to 
that the craw fish so undermined the dam at the mouth of the Aroostook 
River, that it was partially carried iind While craw fishes are most abun- 
dant in the Middle, Western and the Southern States, they are more com- 
mon in New England than one would be led to suppose from Dr. Hagen's 
quently under stones in lakes in Northern Maine, and has had specimens 
from Williamstown, Mass., presented him by Mr. S. H. Scudder. 
Passing over the cinseticstibn and distribution of the species, we will 
glean some results of the author's study on the sexual peculiarities and 
dimorphism of these creatures. He finds that some of the females show 
ferences, such as the greater development of the limbs, the tarsal third of 
which are pening when they are not in the males of the first form, 
and the ** hooks on the third article of the third, or in some groups of the 
third and of the id pair of legs are smaller and less developed. The 
whole body has less size and width, the sculpture is not so well finished, 
while the claws are shorter, narrower, and more like those of the fe- 
male.” He adds that ‘the existence of a second form of the male, if it 
were no more than a passage or metamorphotic form, would not be ex- 
* Illustrated Catalogue of the Museum of yerge Zoology. No. Monograph of 
tne North American Astacidæ. By Dr. H. A. Hagen. Cambridge, 1870. pe al 8vo, pp. 109. 
With eleven lithograph plates 
