Astronomy. 317 
Hai: quarto, 55 pp., 12 plates.—This number contains two me- 
moirs. The first is on Zrionyz, illustrated by 10 lithographic 
plates, by P. M. Heude. Thirteen species are described, These 
are referred to nine genera, viz: Yuen (five species), Psilogna- 
Gomphopelta, Colognathus, Tortisternum, 
Ceramopelta, Captopelta, Cinctisternum. The second memoir, 
: ude i G. Rarnovis. It i 
illustrated by two plates, showing both sexes and their trans- 
formation, wi e anatomical details. We understand that 
d 
vr. Astronomical Papers of the American Ephemeris; Vol. 1. 
fashington, 1882.—This is the completed volume containing six 
of Venus on Mercury, by G. W. Hill. 
2. Transits of Mercury 1677-1881.—The sixth of the above 
Papers, by Professor Newcomb, is an exhaustive discussion of all 
here in the earth’s rotation on 1ts aXis. rofessor 
between 1750 and 1850, and assuming that the observed inequal- 
Mes in the moon’s mean motion are to be accounted for by 
Actual inequalities in the earth’s rotation, then our measurements 
1 . 
mer by far the most probable. But the transits of Mercury do 
ow a remarkable inequality of the required kind but only one- 
