166 
NON-METALLIC MINERALS. 
72. Amygdaloid of Agate- 
Jasper and Amethyst, with several 
inlets of infiltration, some of which 
only reach the outer layer, but 
others are much deeper: the former 
presence of Calc Spar is distinctly 
shown by the rhombohedral forms 
towards the centre of the agate. 
Galgenherg. 
73. Amygdaloid of Agate- 
Jasper and Amethyst, Muth very 
distinct inlet of infiltration. 
Galgenherg. 
73a. Section of Amygdaloid of 
Agate-J asper and Chalcedony, 
showing inlet of infiltration. 
74. Portion of an Amygdaloid, 
showing an inlet of infiltration 
through Avhich great disturbance 
of the deposits has been caused. 
The hollows are probably due to 
the removal of Calc Spar. 
Galgenherg. 
74a. Irregular deposition of 
Chalcedony, Amethystine Quartz, 
and Agate-Jasper, by several 
inlets. 
75. Amy'Gdaloid of Agate- 
Jasper, Chalcedony, and Ame¬ 
thyst, with hollows due to the 
removal of Calc Spar. 
Galgenherg. 
76 and 77. Portions of Amyg¬ 
daloid enclosed in compact Mela- 
])hyre, the first part of the filling 
being Calc Spar, and the remainder 
Chalcedony. 
Algenroth, near Idar. 
78. Similar Amygdaloid, the 
Calc Spar being more concen¬ 
trically deposited, and the Chal¬ 
cedony introduced by various 
inlets. 
Algenroth. 
79. Amygdaloid externally 
clothed with Delessite, or green 
earth, which is derived from the 
decomposition of the Melaphyre, 
and is generally the first deposit 
in the cavity. The interior is 
filled with Agate-Jasper, showing 
irregularity as produced by several 
inlets of infiltration. 
Galgenherg. 
80. Amygdaloid of irregular 
shape, filled with Agate-Jasper, 
and showing on the back the usual 
circumstance of a first deposition 
of Amethyst crystals. ■ 
Galgenherg. 
80a. Amygdaloid of Agate- 
Jasper and Chalcedony, with De¬ 
lessite, or green earth. 
Montrose. 
80b. Section of an Amygda¬ 
loid of Amethystine Quartz and 
Agate-Jasper, with Delessite. 
R. Till, Northumherland. 
Presented by the Rev. Stopford Brooke. 
81. Fragment of a large Amyg¬ 
daloid, the outer part composed 
! of radiated Amethyst, and the 
inner of onyx-like Chalcedony. 
Uruguay, Monte Video. 
82 . Similar Amygdaloid arti¬ 
ficially heightened in colour. 
Uruguay. 
82a. Concentric Chalcedony, 
partly surrounded with radiated 
Amethystine Quartz, the inlet of 
infiltration being still open. 
82b and 82c. Portions of an 
Amygdaloid, first lined with 
Chalcedony, and then partially 
filled with horizontally-deposited 
Chalcedony. 
82 d. Chalcedony, partly filling 
an amygdaloidal cavity. 
83. Segment of a Chalcedony 
Amygdaloid, the inner layer hori¬ 
zontal, and the outer concentric. 
Uruguay. 
N.B.—In the German Agates no hori¬ 
zontal layers are found. 
83a. Chalcedony in concentric 
and horizontal deposits. 
84. Section of Amygdaloid 
filled with Chalcedoii}^ and Ame¬ 
thyst : the horizontal layers are 
continuous with the concentric, 
