PAPERS RELATING TO NATURAL HISTORq. 191 



aa able as well as earnest cultivator of Malacological Science. 



Among coutributions to Natural Science, published in various peri- 

 odicals which we have received through the kind attention of their 

 authors, we name " Notes on the Embryology of Star-fishes," from 

 the Annals of the Lyceum of Natural History of New York, by Mr. 

 Alexander Agassiz, who follows up, with great credit to himself and 

 advantage to science, the labours of his distinguished father. "Notes 

 on Certain Terrestrial Mollusca, with Descriptions of New Species," 

 extracted from the same work, by Thomas Bland ; " Remarks," by 

 the same naturalist, eminent for his knowledge of Terrestrial Mol- 

 lusks, " on the Origin and Distribution of the Operculated Land- 

 shells which Inhabit the Continent of America and the West Indies," 

 extracted from the American Journal of Conchology ; two parts. 

 This is a highly interesting and valuable paper. We may observe 

 that the author explains that in using the term origin, applied to 

 families, &c., he refers to the country in which there is the maximum 

 specific representation. 



Again, we have from Leo Lesquereux, a paper " On Fucoides in 

 the Coal Formations." This must prove attractive not only to the 

 Geologist and the Botanist ; but, in its discussion of the origin of pe- 

 troleum, will excite the curiosity of the practical man, who would ex- 

 pect to be enabled to judge more satisfactorily of the probable dura- 

 bility of the supply, if he had some good information respecting the 

 origin and history of the substance. Though our quotation must be 

 of some length, we expect our readers will be pleased to see the por- 

 tion of Mr. Lesquereux's paper which relates to the origin of petro- 

 leum : — 



" Does Petroleum Originate from the Decomposition of Marine Plants ? — Con- 

 sidering the question of the origin of our deposits of petroleum, some geologists 

 have expressed the opinion that they might be due to the decomposition of 

 marine plants, as coal is the result of the decomposition of a terrestrial vegeta- 

 tion. This conclusion is but natural, for there exigts an evident correlation 

 between the formation of both kinds of deposits of bitumen. But this'relation 

 cannot be, or at least has not yet been, established by direct proofs or experi- 

 ments, and that is probably the cause why the subject has not been studied 

 more m detail. 



" Fecundity of the Marine Vegetation at the Palmozoic Ages. — There is no 

 doubt that the marine vegetation of the Palaeozoic ages can be compared, for 

 luxuriance, and in some measure for its composition also, to the terrestrial 

 vegetation of the coal epoch. From the Upper Devonian down to the Lower 

 Silurian, some strata of shales are not only covered, but indeed filled, sometimes 



