Mr. Brooke on Monticellite, and other Minerals. 265 



white at their extremities. Each quill-feather of the 

 wings has a broad margin of white on its inner web, 

 and the secondaries and tertials are tipped with white. 

 Upper tail-coverts and feathers of the tail deep cine- 

 reous ; the latter, with the exception of the two mid- 

 dle ones, which are plain, having a border of white 

 on their inner webs. A white collar passes over the 

 back part of the neck, immediately behind which is a 

 narrow parallel band of a chestnut colour. On each 

 side of the breast a black spot is conspicuous. All the 

 inferior parts are white except the thighs, which are of 

 a bright rust colour, and the under coverts of the wings, 

 which exhibit a slight tint of the same hue. Legs and 

 feet yellow. Claws dark horn colour inclining to black. 

 Colour of the eyes not known. Total length 9 inches ; 

 wings, from the carpus to the tip of the second quill- 

 feather, 5y^Q ; upper mandible, from the point to the gape, 

 in a straight line, /„ ; under mandible, -^-q ; tarsi, 1. 

 The specimen from which the foregoing description was 

 taken occupies a place in the Manchester Museum. 



That G. Holmii bears a striking resemblance to the 

 G. S-xainsonii of Mr. Vigors cannot be denied ; the white 

 collar and chestnut-coloured band on the neck of the former, 

 and the pure white plumage of its abdomen, constituting the 

 most obvious points of difference between the two species. 



To Edward Holme, M.D., the learned and accomplished 

 President of the Natural History Society of Manchester, (who 

 has uniformly promoted my zoological investigations by every 

 assistance which his extensive knowledge and valuable library 

 could supply,) this bird is respectfully dedicated. 



XXXIV. On Monticellite, a new Species of Mineral; on the 

 Characters of Zoizite ; and on Cupreous Sulphate of Lead. 

 By H. J. Brooke, Esq. F.R.S. L.S. ^ G.S.* 



Monticellite. 

 ¥ OBTAINED a year or two since from Mr. G. B. Sowerby, 

 ■*■ a specimen said to have come from Vesuvius, containing 

 some imbedded crystals of a substance which I believe has 

 not been before noticed, and of which I am not aware of having 

 seen any oilier specimen. The matrix is crystalline carbonate 

 of lime; and besides the mineral I am about to describe, it 

 contains particles of black mica, and some minute crystals of 

 pyroxene. On tlie supposition of its being an undescribed mi- 

 neral, and from Vesuvius, I have named it after Mr. Monti- 

 * Communicntcil by the Autlior. 

 N. S. Vol. 10. No. 58. Oct. 1831. 2 M celli, 



