Correspondence. 119 
Mineralojiy : V>y Frank Riitloy. ;5rd Kilition, Itiino, 241 pp. ThomuB 
Murby, London. 
Ueber die Erdbeben der kapathen-und-karstbindcr. Bericbte der 
nngaiHcbeu and kroatischen Erdbeben-ComniisHionen. (In tbe geol. 
Mittbeil. Zeit. derungarn, geol. (ienelb Jan.-Marcb, 1889.) 
Der Loss von Briinn und seine Ein.scbliisse an dihivialen Tliieren 
und Mensclien. .1. Mnkowshj. Verband.d. nat. Ver. in Briirnn. x.wi, 
Band, ISSS. 
Ueber die Vervendnng einer Schefelkugel zur Demonstration singu- 
liirer Scbnitte an der Strablonfliiclie ; von .1. Schrauf, aus Annalen der 
PIn/sikniul Chemie. Bd. xxxvii, 1889, Leipzig, 
The history of volcanic action during the Tertiary period in the 
British Isles. By Archibald Geikie. 4to 184 pp. Map and woodcuts, 
Robert Grant and son, Edinburgh ; P^ighteen shillings. 1888. 
Reports of geological explorations during 1887-88, with majo and 
sections (New Zealand.) By Jainca Hector. Embraces also reports by 
Ale.i under McKay and Jamex Park. 
Ueber einige Bestandtheile des Meteoreisen von Magura, Arva, Un- 
garn. Von E. Weinscheiik; Clintonit aus dem Meteoreisen von Magura, 
Arvaer Comitat. Von Dr. Aristides Brezina. 
CORRESPONDENCE. 
Note on the Distribution of Certain Loess Fossils. — Throughout 
Iowa and portions of the contiguous states the loess forms a marked fea- 
ture along the principal lines of drainage. Its characteristic topography 
readily distinguishes it, at a distance, from associated glacial deposits. 
Everywhere over the area referred to the loess is to a greater or less 
extent fossiliferous. AVith a few exceptions the fossils are shells of mol- 
lusca, whieh are often very abundant, and are easily recognizable, by a 
peculiar chalky whiteness, from "dead" shells of the same speciesstill 
extant. There are now known from the loess of Iowa about thirty-five 
species of mollusks. Of these three-fourths are land forms ; the re- 
mainder aquatic. 
The species found in' the loess which at present appear to be extinct 
over portions, or all of the area just mentioned are : Patiila strigosa 
Gould, Pupa Idandi Morse, Pupa muscorum Linn^, Vertigo simplex 
Gould, }fe$odon thyroidea Say, VaUonia ptdchella Miiller, and Heli- 
cina occidta Say. It is to be noted that all seven of these gasteropods 
are terrrostrial, and that they are among the most characteristic and 
persistent forms of the deposit, usually occurring in greater or 
less abundance wherever the loess is present in the Mississippi 
Valley. The first four species listetl are at the present time extra lim- 
itary ; Vertigo sirnplex, Pupa blandi, and Pupa muacornm being boreal 
forms, the latter also circumpolar in its distribution. The other 
three species enumerated are not found living in central Iowa, ifeso- 
don thyroidet Say occurs, however, in the eastern partof the .state along 
the Mississippi river. VaUonia pulchella and Jlelicina occulta also are 
