122 Revietvs — Gumhel &}i " Nullipores." 



While objecting to most of tlie views of geologists, wliicL, how- 

 ever, he frequently distorts, Mr. Mallet claims the character of 

 physical truth for his own ideas. 



The only one which appears original, or nearly original, in his 

 theory is, that Volcanic heat and force is wholly evolved from the 

 crushing of the subsiding solid shell of the globe under secular 

 cooling. 



Strange to say, Mr. Mallet wholly overlooks the fact that the 

 secular cooling of a superheated nucleus already provides heat 

 enough for volcanic purposes, so that to imagine another wholly 

 different source of heat arising from the collision and crushing to- 

 gether of the broken fragments of the crust is quite superfluous. To 

 imagine, in short, two sources of heat, when one, and a recognized 

 one, suffices to explain all the phenomena, is most unphilosophical, 

 especially in one whose claims to high consideration are mainly based 

 upon his mathematical accuracy. On other, and especially on chemi- 

 cal and mineralogical grounds (as pointed out by Mr. David Forbes 

 in "Nature," Feb. 6th, 1872, p. 261), Mr. Mallet's theory is not 

 likely to meet with a ready acceptance. 



Those who wish to read in English Prof. Palmieri's account of 

 the 1872 eruption, will find the present edition — with the exception 

 of some slight faults in translation, and a few errata in printing — 

 serve their purpose excellently well ; we should have preferred, 

 however, to keep Mr. Mallet's Introduction distinct from Professor 

 Palmieri's Eeport. 



11. Dr. C. W. GiiMBEL ON THE SO-CALLED " NuLLIPORBS;" AND 



THEIR Participation in the Composition of Calcareous Eocks 

 ("Die sogenannten Nulliporen," &o,). From the Transactions 

 of the Bavarian Academy of Sciences, 1871 and 1872. 



OF the many obscure fossils that pass from hand to hand among 

 working paleontologists, waiting until a matured knowledge of 

 nature assigns them to this or that group with certainty, the so-called 

 " Nullipores " have been by no means the least vagrant ; they have 

 received as many synonyms as they have had observers. Bringing 

 the microscope and an intimate knowledge of both microphytes and 

 microzoa to bear on them. Dr. Giimbel, of Munich, resolves the 

 known fossil " Nullipores " into two kinds — 1. True calciferous 

 Algae {lAihoihamnium, and an allied form Lithiotis) ; and, 2. Forami- 

 nifera (Dactyloporidea) . In the first category he describes (1871, 

 pages 13-52, plates i. and ii.) : — 



1. Lithothamnium ramosissimum (Eeuss). — Middle Tertiary. 



2. L. nummuliticum, Giimbel. — Lower Tertiary. 



3. L. effusum, Giimb. — Lower Tertiary. 



4. L. pliocanum, Giimb. — Upper Tertiary. 



5. Z. tuberosum, Giimb. — Lower Tertiary. 



6. L. torulosum, Giimb. — Lower Tertiary. 



7. L. mamillosum, Giimb. — Upper Chalk. 



8. L. Farisiense, Giimb. — Lower Tertiary. 



9. Z. Jurassicum, Giimb. — Sponge-rock with Amman, bimammatus, 

 10. L. proccenum, Giimb. — Upper Chalk. 



