432 Miscellaneous. 



amined numbers of specimens of Atrypa, showing sections of tlie 

 spires, and lie has observed that the volutions composing the cones 

 vary in number, with the increase in age and size of the shell ; 

 while specimens of the same size have about the same number of 

 volutions. 



Analysis of a Black Spinelle. — M. Pisani has communicated 

 to the Academy of Sciences, Paris, the analysis of a black spinelle 

 from the Haute Loire. It is as follows : — 



Alumina 59-06 I Ferrous Oxide 13-60 



Ferric Oxide 10-72 | Magnesia 17-20 



It is remarkable from its crystalline form — an octohedral pyramid — 

 which has not before been recognized in spinelles. This mineral is 

 chiefly found in Haute Loire, but it is also met with in the igneous 

 rocks of Auvergne. — ■ Comptes Bendus. 



ERRATA FOR JULY AND AUGUST. 



Page 300, line 6, from top of page, for " Surturbrand " read Surturband. 



„ 321, „ 9, from foot of page, for " silicia " read silica. 



„ 327, „ 25, from top of page, for " breach " read beach. 



„ 375, „ 24, ,, „ for " outline " read " OM^Jier." 



„ 382, ,, 5, from top of page, for " Ordnance Memoir," read " Geological 



Survey Memoir," 



„ „ „ 6, from top of page, for " Hall " read " Hull." 



Dr. T. Stebry Hunt's Lecture.— "We hoped to have received from Dr. Sterry 

 Hunt some corrections of the Short-hand Writer's Report of his Lecture at the Royal 

 Institution, on "The Chemistry of the Primeval Earth," — (See Geol. Mag. for 

 August, p. 357,) — but his unexpected departure for Canada having prevented, we 

 hasten to give such errata as we have been enabled, with the assistance of our- col- 

 leagues, to detect, and, at the same time, we beg to apologise to Dr. Hunt for their 

 occui-rence : — 



Page 361, line 26, from top of page, for "increases the act of fusion," read " raises 

 the melting point." 

 „ „ „ 38, from top of page, «?efei!e "largest." 

 „ 362, „ 11, „ „ for "the metallic bases" read "the other 



metallic bases." 

 „ „ „ 25, from top of page, after the words " may be absorbed," insert 



" and given off." 

 ,, „ „ 16, from foot of page, for "seven times" read "several times." 

 ,, 363, „ 11, ,, „ for "consist only of lime," etc., read "contain 



only lime," etc. 

 „ 364, lines 14 and 15, from foot of page, for "the remains of calcareous 

 animals " read " the calcareous remains of animals." 



„ 365, line 39, from top of page, for " disruptive " read "eruptive." 



j^ ^j 40 ,, „ for " decomposed " read " recomposed." 



" 36'6, ,, 24, from foot of page, for " Orchid-house" read "Orchard-house." 

 „ 367, „ 4, „ ,, for " Thompson " read " Thomson." 



J, „ ,, 5, ,, „ for " mutation " read "nutation." 



„ 368, „ 17, from top of page, for "radiation" read "convection." 

 „ „ „ 19, „ „ for "gault" read "Co«;." 



We should, in fairness to Dr. T. Sterry Hunt, state that, owing to his absence in 

 Paris during the month of July, we were unable to submit a proof of the Report, for 

 his correction, before its publication in the August Number of this Magazine ; and 

 thus the errors above stated escaped detection, — Edit. 



