Miscellanies. 393 
19. Monograph of the Limniades, and other Fresh Water Uni- 
valve Shells of North America: by S. S. Haldeman, Philadelphia. 
Judah Dobson, July, 1840. No. 1. 8vo. 
The specimen number of a series bearing the above title, reached 
us last January, and was duly acknowledged in the list appended to 
the 78th number of this Journal. 
The object of the work is to fill the space left unoccupied by the 
labors of Messrs. Lea and Conrad on the Unionide, and Mr. Binney 
on the Helices. The plates are executed in fine style, on copper, 
drawn by Miss Lawson, and colored very beautifully, with five or six 
examples of each species. The following species of Paludine are 
contained in the first number,—decisa, Say; subcarinata, Say; inte- 
gra, Say; ponderosa, Say; genicula, Conrad. Mr. Haldeman des- 
cribes five new Mollusca and parasitic animals, viz. Anculosa littori- 
na, from Holston river, Va.; Cerithium (Potamis) Californicum, 
hab. California, Mr. Nuttall; Cyclas elevata, hab. near N. Orleans; ° 
Hirudo (Clepsina) scabra, found on Planorbis bicarinatus; Cercaria 
hyalocauda; parasite of Physa heterostropha. He also proposes to 
establish a new genus Discus, for the reception of Planorbis armi- 
gerus, Say; its characters are the same as Planorbis, with the addi- 
tion of the teeth situated within the aperture of the shell. Each 
number will contain five plates and descriptions, and costs $1 per 
number, and may be had of Mr. Dobson. 
20. Leonhard’s Geology. (Géologie des Gens du monde, par K. 
C. de Leonhard, conseiller intime, professeur a Vuniversité de Hei- 
delberg: traduite de l Allemand sous les yeux de Vauteur, par P. 
Grimblot et P. A. Toulonzau. Tome deuzxiéme, Paris et Stuti- 
gart, 1840, pp. 484, 8vo-) = 
This is the second volume of a series of three, in course of publi- 
cation, by the celebrated author of the Hand-book of Mineralogy, 
and Editor of the Jarbuch fir Mineralogie, &c. We have not seen 
the first volume, and are therefore unable to speak of it in connee- 
tion with the present; but the second is evidently a continuation of 
the first, and not an independent treatise. It commences with an ac- 
count of the prismatic divisions and vesicles of the voleanic and Plu- 
tonic rocks, and their action on the other rocks. He then proceeds 
in the usual order, through the superincumbent strata to the top of 
the coal. But the work is enriched throughout by every attraction of 
style and illustration, and the author has brought, to the elucidation 
of his subject, all the resources of a highly cultivated and accomplish- 
ed mind. He is by no means confined to the mere technical details of 
his science, but draws interest from every source. Thus, at the con- 
