286 



THE GEOLOGIST, 



Imperial Museum of Mineralogij, Vienna, Apil 30, 1B60. 



My Dear Friend, — I beg leave to submit to your kind judgment 

 the leading views of my second paper on the distribution of Bracliio- 

 poda, published by our Academy a short time ago. 



In a first paper on this subject, I have tried to unite the facts relat- 

 ing to the geographical and bathymetrical distribution of living Bra- 

 chiopoda, and have arrived at the conclusions : 1st, That the geo- 

 logically ancient genera (Terebratula, Rhynchonella, &c.), are sjjomdic, 

 and only some genera of newer date (Krausina, Morrisia) may, 

 perhaps, be termed endemic genera ; 2nd, That Brachiopoda are found 

 living in every climate, but that the genera with translucid shells 

 (Lingula, Discina) are confined to warmer seas ; 3rd, That these 

 same genera with translucid shells are only found within very 

 moderate depths, most of them within seven fathoms, the genera 

 with opaque shells (Terebratula &c.) inhabiting, on the contrary, 

 greater depths, with a very small number of exceptions. Some of 

 these latter live even in very considerable depths. 



My subsequent papers were intended to give my views on the 

 habitations of fossil Brachiopoda, and so I have given a chapter at 

 the beginning of my second paper, which contains some general 

 remarks on the life of species, and on the influence of a change of 

 external conditions on the distribution of animals. It is not this part 

 of my paper I wish to speak of now ; if you should wish for it, I 

 might give you an analysis of it in some other letter, and you would 

 find a new classification of our Tertiary beds in it. Before I enter 

 into further details, it is sufficient to extract the following conclusions 

 from this chapter: — 1st, A change of level, which produces an 

 extension and communication of marine provinces, will produce dimi- 

 nution and isolation of terrestrial provinces, and vice versa. 2nd, 

 Because the vertical range of bathymetrical zones increases with the 

 depth, an oscillation may produce greater changes in the upper than 

 in the deeper zones. Besides this, the littoral and sub-littoral zones 

 are exposed to certain influences, which do not penetrate into the 

 deeper zones, so that external changes may cause great variation in 

 the upper zones, the fauna of the deeper sea remaining the same. 



1853. — " On the Brachial Apparatus of Thecidea." Acad. 8vo., three plates. 

 1S5 1. — " On the Brachiopoda of Ivossen Strata. Acad. 4to.j foiu- plates. 

 1853. — " On the Brachiopoda of the HaUstatt Strata." Acad. 8vo., two plates. 

 185G. — " Gorman edition of Davidson's Classification of the Brachiopoda." 

 dto., five plates. 



^ 1858. — " On the Brachiopoda of Straniberg Strata in Haner's Beytrage." 4to., 

 six plates. 



185i). — "Note sur la Waldhemia Stcphanis in Palason." Lonib. 4to., one 

 plate. 



„ . — " On the Distribution of Brachiopoda." Th-st paper. Acad. Svo. 

 •>■> ~ 55 35 „ Second paper. „ „ 



In additit)n to these, Prof Sucss has published several other papers relating to 

 the Geology of the Alps, etc. 



