428 



that he does not think such a coincidence has been noticed else- 

 where. At any rate it has not been so absolutely established 



Transitional states of the characteristic, if they may be so 

 called, are also seen in the Rouge River mound ; that is. instances 

 in which the communication between the fossa? is not quite com- 

 pleted, the dividing wall being reduced, in some cases to a very 

 thin partition, almost transparent. Even where the perforation is 

 accomplished, there is a great variation in the size of the aperture. 

 — Henry Gillman, Detroit, Michigan. 



MICROSCOPY. 



Atlas der Diatomaceen kunde.— By Adolf Schmidt, assisted 

 by Grundler, Grunow, Janesch, Weissflog and Witt. Publishing 

 in parts, each with four plates. To be completed in from twenty- 

 five to thirty parts. Three parts of this magnificent work have 

 been received. Each plate contains from fifteen to forty figures. 

 The plates are from photographs of original drawings, reproduced 

 by some one of the processes for copying photographs. It is said 

 that nine thousand drawings have been prepared for the work. 

 Size of the plates, fourteen by nine and one-half inches. 



It seems to be the aim of the editors to give every known vari- 

 ation of each species of Diatom. For example, plate seven has 

 forty variations of the type Navicula Smithii Breb. = 3 r . eUiptka 

 W. S. Other genera and species are treated in the same manner. 

 Two plates with eighty-nine figures are devoted entirely to the 

 panduriform Navicula. The editors are the most renowned stu- 

 dents of this department of natural history in Germany, and the 

 work will be indispensable to all workers in this country, to 

 whom the writings of the German diatomists have been almost 

 inaccessible, scattered as they are among the German periodicals, 

 while for the bibliomaniac it will supply one of the great books of 

 the age. — C. S. 



Measurement of Moller's Probe Platte. 1 — Mr. A. F. Dod, 

 Secretary of the Memphis Microscopical Society, Memphis, 

 nessee. Dear Sir: I have this day finished the measurement of 

 your probe-platte, No. 5S6. The first thirteen were measured 

 on the evening of March twenty-ninth, by lamp-light ; the rest 



