936 The American Naturalist. [November,. 
side of the quartz, thus exposing again the unusual faces. Some of the 
calcite layers are still present in the specimen. 
The new mineral lawsonite is more fully described by Ransome and 
Palache” than was the case in the original paper by Ransome. The 
formula is H, Ca Al, Si,O,,.—Walker™ finds that the sperrylite from 
the Sudbury district probably occurs originally included in chalco- 
pyrite. The new face z (10.5.2) was observed. The suggestion is 
made that Os and Ir occur replacing Pt in sperrylite, and an analysis 
of the products of the Murray mine, showing the presence of these ele- 
ments, is given. (If, as this analysis would indicate, the two elements. 
osmium and iridium are present in an amount equal to one quarter 
that of the platinum, it is difficult to suppose that they exist in the 
sperrylite, since Wells states specifically that he found no iridium in 
the sperrylite analyzed by him).—Adams and Harrington” describe a 
new alkali-hornblende chemically near an orthosilicate, and a titanifer- 
ous andradite from the nepheline-syenite from Dungannon, Hastings. 
Co., Ontario.—Merrill® notes an occurrence of free gold in a black 
mica granite from Sonora, Mexico, apparently as an original constitu- 
ent of the rock.—Crocoite crystals from Mt. Dundas, on the west coast 
of Tasmania, measured and figured by Palache" present, in addition to- 
the twelve known forms the new, though doubtful, prism (10.3.0). 
GEOLOGY AND PALEONTOLOGY. 
Permian Land Vertebrata with Carapaces.—In the NAT-- 
URALIsT for 1895 (November) I deserived wader the name of Disso- 
rhophus a new genus of probabl halia with an 
armadillo-like carapace. In the Proceedings of the ‘American Philoso- 
ical Society for the same year and month I described a new family of 
Cotylosaurian Reptiles protected by a similar structure. These con- 
stitute the only forms of land vertebrates so constructed known from. 
the paleozoic formations. The nearest approach to it previously 
known from the Permian is seen in the genus Zatrachys, where the. 
18 Zeitschr. f. Kryst., XXV, pp. 531-537, 1895. 
4 Zeitschr. f. Kryst., XXV, pp. 561-564, 1895. 
15 Amer. Jour. Sci., CLI, pp. 210-218, 1896. 
16 Am. Jour. Sci., CLI, pp. 309-311, 1896. 
11 Am. Jour. Sci., CLI, pp. 389-390, 1896. 
