498 Mbieralogical Notices. 



Trochus is escutcheon-shapedj and its tentacles more delicate 

 and shorter. 



The true synonymy then would be as follows ; 



Trochus nodulosus, Gmel. 



Littorina trochiformis, Dillw. ; Syn : Trochus tuberculatus, 

 Wood's Sup. ; Litt. tuberculata, Menke and Desh. ; 



Litt. dilatata, D'Orb. (var.) 



ART. XLII. — MINERALOGICAL NOTICES. By J. E. Teschemacher. 



GLAUBERITE, brought from Tarapaca, Peru, by Mr. John H. Blake. 



This mineral is found in small crystals, which are imbedded 

 in a beautiful, silky, fibrous borate of lime, published in 

 Alger's edition of Phillip's Mineralogy, under the name of 

 Hayesine. 



This Glauberite was analyzed by A. A. Hayes, and found 

 to contain 



Sulphuric acid, 57.220 



Soda, 21.324 



Lime, 20.680 



Iron, .444 



It is essentially a compound of sulphate of lime and sulphate 

 of soda. The first crystals I measured, the figure and meas- 

 urements of which are in the last edition of Dana's IMineral- 

 ogy, were extremely dull, so that I could only consider them 

 as approximative. Mr. Hayes afterwards sent me some 

 extremely brilliant crystals, the measurements of which coin- 

 cided exactly with those of the Glauberite, from Villa Rubia, 

 in Spain. The figure above named is that of th'6 first crystals 

 I found. Subsequently, others came to light, of very differ- 

 ent forms, produced by other modifications. 



It is stated, in Dana, that, if crystals of Glauberite are left 

 in water, they will at length fall to pieces. This is probably 

 true. Those from Tarapaca, if treated carefully with cold 

 water, will permit nearly all the sulphate of soda to be dis- 



