Notices of Memoirs — Snow Dust. 511 



decalcification would cause a false conception to be taken of the 

 protozoan life. 



IV. The Nodule Bed; zone a, originally exposed at Sutton (see 

 above). — In the exposui-es now open, as at Foxhall, the mixed and 

 remanie character of the deposit precludes any trustworthy infer- 

 ences being made from such specimens as might be found. 



Note. — Some Foraminifera derived from much older Tertiary beds 

 were found by Mr. Searles V. Wood in the Coralline Crag of Sutton 

 and elsewhere, namely, OrbitoUtes, Orbiculina, AlveoHiia, Peneroplis, 

 Amphistegina, Nummidites, and Orbitoides ; mostly unique specimens. 



Tlie value of Foraminifera as a means of establishing strati- 

 graphical correlation, with few notable exceptions, such as Nummn- 

 lites and Fusidina, has not perhaps been so fully recognized as it 

 might be. 



In the Coralline Crag the most strikingly constant Foraminifer is 

 Pohjmorphina frondiformis, and this species appeal's to be charac- 

 teristic of this horizon in England. So far as I am aware, it is not 

 met with in the Antwerp Crag. I have collected and examined 

 material from the Casterlian and Scaldisian of the Kattendyk 

 Docks, but have not found this species ; nor is it recorded from 

 the Diestian. May this not prove that the Antwerp beds are of 

 somewhat different age to those of England ? 



The "constancy and determinability " of the zones established by 

 Professor Prestwich for the Coralline Crag were doubted by Messrs. 

 S. V. Wood, jun., and F. W. Harmer ; but the foregoing notes tend 

 to prove that there is good ground for accepting his subdivisions. 

 The exact correlation of isolated patches of the Crag is not in all 

 cases easily establit-hed ; and further research is needed to finally 

 settle the relationship of sonie of them. 



So far as my researches on the Mollusca of the Crag have extended, 

 and I have collected for several years from almost every exposure 

 now open, they confirm the zonal arrangement of the beds. The 

 band with Arciica islandica is apparently constant to zone d. At 

 Sutton and Gedgrave, points widely separated in the Crag area, 

 zone / is characterized by the relative abundance of species which 

 are either absent or rai'e in other zones ; among such may be named 

 Bullinella acuminata, B. conulus, Adeorbis suhcarinatus, A. pulchralis, 

 Trochus obconicus, Raplutoma brachystoma, Tm-bouilla elegantior, Lima 

 ovata, and others; while some species, though not so distinctive of 

 this zone, are far more abundant than in any other, such as Ringicida 

 bnccinea, Ccecum mammillatnm, Trif oris perversa, Astarte Forbesi, and 

 other species. 



zsroTic!:Es OIF ZMZEivnoiias. 



Snow Dust. By Prof. Cleveland Abbe. Monthly Weatlier Eeview, 

 January, 1895, pp. 15-19. (U.S. Weather Bureau.) 



ON the night of January 11-12, 1895, a shower of dust in con- 

 nection with snow fell throughout a large part of Indiana and 

 Kentucky. The dust may have been intermingled with snow in 



