Correspondence — Prof. Owen. 143 



TALOVLOTBERITJM ANNECTENS, Owen. 

 Sir, — Tho Bpecimens described, Juno, 1847, as of Paloplotherium 

 annectens, being of an immature individual witli the last lower 

 molar, en germe, in its formative alveolus (Quart. Joiim. Geol. Soc. 

 Vol. iv. pi. 3, fig. 4) tho hind lobule was not calcified. Subse- 

 quently receiving from HordwcU the mandible of an adult, I had it 

 placed by the side of the first specimen, and labelled witli its name 

 in the British Museum. The rapid accumulation of materials has 

 delayed the Second Edition of my " British Fossil Mammals ;" but 

 the rectification of the characters of Paloplotherium was made by 

 PiCTET in the Second Edition of his excellent " Traite de Paleonto- 

 logie," vol. i. p. 312 (" la dernierc a trois lobes.") 



KicHAKD Owen. 



THE LIQUEFACTION OF ROCKS AND " VOLCANOS." 



Sir, — My error against Dr. Sterry Hunt and Mr. Scrope, conjointly, 

 was committed in the pages of Scientific Opinion, and I acknow- 

 ledged it in the same publication as soon as Dr. Hunt had shown mo 

 that I was wrong. I suppose that I did not read Dr. Himt's paper, 

 when it appeared in the Magazine in June last. 



But I submit that that has not disposed of my letter to you, written 

 a year ago.^ For in the sentence which he quotes from " Volcanos," 

 p. 266, it is evident that the author is referring to changes in the 

 condition and mass of the volcano itself; because he immediately 

 instances the sealing up of a fissure by cooled lava, and the accu- 

 mulation of ejected matter. Changes of pressure,- arising from 

 movements in the earth's crust, through the cooling of its general 

 mass, are not suggested. 



I am bound to thank Dr. Hunt for his favourable mention of my 

 paper as a whole. 0. Fisher. 



F.8.— Erratum, at p. 59, line 21, for " fused," read " glassy." 



nycisoiBXjXjj^n^iEOTJS. 



Professor Owen has recently received, with remains of Diprotodon, 

 etc., from the lacustrine deposits, Darling Downs, Australia, portions 

 of a Crocodile, in similar fossil condition, which he determines to be 

 identical with the species of Crocodile still existing in the Queens- 

 land rivers. 



Illustrative GsoLoaY and Pal^ontologt. — A very effective 

 chart of British Geology, suggested by Mr. Henry Cole, C.B., 

 for the Technical Education System, has been recently carried 

 out by Mr. James E. Gregory, geologist, of Eussell Street, Covent 

 Garden, and is placed in the South Kensington Museum. It 

 is chiefly compiled from, and intended to illustrate, Professor 

 Morris's Geological Chart. The names of the formations, the 

 uses to which the rocks are applied in the arts, and the localities 

 where they are best exhibited, are duly enumerated on cardboard, to 

 ■which are attached, in parallel lines, various fossils and a few rocks, 

 ^ Geol. Mag., Vol. yi., p. 45. 



