MISCELLANEA. 



221 



in perfectly flat surfaces, these are nacreous in appearance^ 

 Its colour is analogous to that of the hyacinth (ferro-zirco- 

 nite), or yellowish ochre passing into reddish brown ; it is 

 opaque ; scratches gypsum, but is softer than mica. The 

 primitive crystalline form is the rhomboid, and the specific 

 gravity is 2*878. According to Plattner, it is composed of 

 phosphoric acid, and hydrous oxide of iron. — Breithaupt, 

 in Journal f. Pract, Chimie, No. XX, p. 66. 



On a Human Skull transformed into Limonite 

 AND Lignite. — This skull was in the collection of the late 

 Mr. Teschen ; and although transformed into a brownish 

 earthy mass, preserves its form ; it weighs about seven 

 pounds, and when minutely examined, the substance pre- 

 sented none of the characters of the original bone ; and, 

 judging by its external characters, it is intermediate between 

 lignite and an earthy oxide of iron, from which Mr. Kersten 

 considers that it has been partially transformed into lignite 

 and partially into limonite. He also concludes, that having 

 by chance fallen into a deposit of the former, the change 

 has taken place by degrees. — Mr, C, Kersten, in VInstitut, 

 No. 423, p. 47. 



The Glyptodon. — A valuable addition has been made 

 to the museum of the College of Surgeons by the arrival, 

 from the neighbourhood of Buenos Ayres, of a fossil wonder^ 

 to which the name of the Glyptodon has been assigned by 

 Professor Owen. The Glyptodon was a giant armadillo, 

 and some idea of its appearance may be formed, from the 

 fact that when the Carapace was first seen, it was mistaken 

 for a cask. This specimen is unique, and affords a gratify- 

 ing illustration of the advanced state of comparative ana- 

 tomy 3 for whilst Dr. Buckland supposed that the fragments 

 of horny covering, sent to the College of Surgeons by Sir 

 Woodbine Parish, belonged to the Megatharium, Professor 

 Owen maintained that they belonged to some other animal. 



