66 Analysis of Periodical Works on Natural History. 
very deserving and industrious botanist Mr. Baxter of the Ox- 
ford botanic garden, who received it a year or two. ago from 
Brightwell in Berkshire, where it was found naturalized. 
We lay down the volume, under a sense of the highest re- 
spect for its excellent author, and will venture again to express 
our earnest hope that he will not remit in his labour until he 
has completed the Flora of Great Britain, and thus supplied 
us with a text-book worthy of the advanced state of science. 
Just published. 
New Tables of Life Contingencies ; containing the rate of 
mortality among the members of the Equitable Society, and the 
values of life annuities, reversions, &c. computed therefrom ; 
together with extensive tables deduced from the Northampton 
rate of mortality, exhibiting the single and annual premiums 
for assurances on the joint existence, or last survivor, of two 
lives, or on one life against another, and the values of policies 
on single lives. ‘To which are prefixed, a number of practical 
examples, illustrative of the application of the tables; and a 
new method of deducing the values of life annuities, &c. | By 
Griffith Davies, actuary to the Guardian Assurance Company. 
ANALYSIS OF PERIODICAL WORKS ON NATURAL HISTORY. 
Zoological Journal. No. VII. 
This number contains the following articles :— Descriptions 
of thirteen Species of Formica, and three of Culex, found in the 
Environs of Nice, by Dr. Leach.— Descriptions of Neotoma 
Floridana, and Sigmodon hispidum, new mammiferous animals, 
of the order Glires, by Messrs. Say and Ord: from the Journal 
of the Philadelphia Academy.— Monograph of the Box Tor- 
toises, by Mr. Bell: a new genus, Sternotherus, is described in 
this monograph, which is thus characterized: ‘* Sternum uni- 
valve : lobus anterior mobilis, lobi duo posteriores connexi, im- 
mobiles.”—On two Genera and several Species of Crinoidea, by 
Mr. Say: from the Journal of the Philadelphia Academy.— 
Additions to Mr. Say’s paper on Crinoidea; Notice of a Fossil 
belonging to the Class Radiaria, found by Dr. Bigsby in Canada ; 
and Descriptions of two new Species of the Genus Orbicula; by 
Mr. G. B. Sowerby.—On Leptophina, a group of Serpents com- 
prising the Genus Dryinus of Merrem, and a newly formed 
Genus named Leptophis, by Mr. Bell.—Generic and Specific 
Characters of Ophidian, Chelonian, and Batrachian Reptilia, 
discovered by M. Spix in Brazil: from the splendid works on 
the Brazilian Reptiles by Spix and Wagler.—On the Genus 
Psaris of Cuvier, with an account of two new Species, P. crista- 
tus 
