232 



THE AMERICAN MONTHLY 



[October 



Diploneis Grundlerii. 

 Diploneis incurvata Greg. (CI.) 

 Diploneis interrupta. 

 Diploneis Smithii Breb. (CI.) 

 Navicula arabica Grun. 

 Navicula Braziliensis Grun. 

 Navicula circumsecta. 

 Navicula digito-radiata Greg. 

 Navicula formosa Greg. 

 Navicula irrorata Grun. 

 Navicula palpeboralis. 

 Navicula peregrina K. 

 Nitzschia fasciculata Grun. 

 Nitzschia obtusa Sm. 



Nitzschia sigma Sm. 

 Nitzschia Tryblionella Grun. 

 Pinnularia jarrensis (Grun.) CI. 

 Pinnularia viridis K. 

 Plagiogramma Gregorii. 

 Plagiotropis seriata CI. 

 Pleurosigma affine Grun. 

 Pleurosigma Balticum Sm. 

 Pyxilla baltica Grun. 

 Raphoneis amphiceros E. 

 Stauroneis Gregorii. 

 Surirella fostuara E. var. 

 Surirella striatula Turpin. 



The samples furnishing the above forms were taken about four 

 feet from the surface. Otlier strata furnish many other varieties, 

 among them Coscinodiscus stibtilis, Ti-icerathia favus^ Suri- 

 rella regina, S. ovata^ etc. Pits some miles further north show 

 a marked diflerence in the deposit. At Shares' Pit the stratum 

 of sand is wanting, the diatomaceous deposit lying directly upon 

 the red clay, and containing more brackish-water forms. The 

 tidal currents flowing through the ditches in some parts of 

 this marsh contain great numbers of living forms ; at one 

 place I find abundance of what appears to be Pleuro- 

 sig-ma Terryanum and another small Pleurosigma that 

 I cannot distinguish from Colleto?tema eximizmi^ but this 

 is not a Colletoizema in this locality, but an independent and rapid 

 traveller like any other Pleurosigma. Melosira B or ereii grows 

 in quantity on the short grass at the bottom of the rapid current, 

 with Biddulphia Icevis in abundance ; Bacillaria paradoxa 

 makes the most remarkable showing here of any locality in which 

 I have found it. The presence of fresh-water diatoms in these 

 marine deposits has no special significance ; the mud brought 

 down during freshets in the rivers and streams contains diatoms 

 from the ponds and marshes, these are distributed by the tides, 

 and all shore deposits contain more or less of them. When living 

 specimens are found in any quantity it shows that the water con- 

 tains very little salt. In a shallow pool on the margin of the 

 marsh into which the tidal waters flow, I find Surirella elegans 

 and many other fresh-water kinds in vigorous life, and also the 

 very small and delicate Plezirosigma ctirvula and Amphiprora 

 nereas. 



Hsematozoon of Malaria. — Dr. P. Hehir, of the Nizam's 

 Medical School at Hyderabad, has published an account of his 

 microscopical ol)servations on the hajmatozoon of malaria. He 

 looks upon the htematozoon as a polymorphic organism. 



