14 MR. M. T. MASTERS ON THE 
the Himalayas, as many in Japan and China, One inhabits 
Kamtschatka, and one N.W. America. There are three species 
in Mexico, four in the Eastern United States, and one in the 
West Indies. J. communis is distributed throughout the whole 
of Europe, in Siberia and Kamtschatka, especially in the form 
called alpina or nana, which occurs also both in Eastern and in 
Western North America. On the Alps this species extends 
upwards to 5000 feet. 
In a fossil condition, according to Renault, Bot. Fossile (1885), 
p- 185, it occurs in Tertiary strata, in amber &c., but not fre- 
quently. Hither its remains have not been preserved, or the 
genus, in spite of the simplicity of its structure, is of relatively 
late origin. 
TETRACLINIS. 
Under the name of Thuya articulata a remarkable Conifer, 
native of the Barbary States, was mentioned in Shaw’s ‘ Travels 
in Barbary ’ (1738), and botanically described by Vahl in 1791. 
It was known to the Romans, who highly valued its timber, 
which is still used for ornamental purposes. Desfontaines 
adopted the name given by Vahl, but as the characters of the 
plant differ in many respects from those of Thuya, it has of late 
been generally included under the genus Callitris, of which 
Frenela isa synonym. Richard, Spach, Endlicher, Parlatore, 
and Ball all attribute the species Callitris quadrivalvis to Vent- 
enat; but this, as was pointed out by Bentham, is an error, as 
Ventenat, when founding his genus Callitris upon an Australian 
evergreen tree, mentioned no species at all byname. Richard is 
responsible for the name Callitris quadrivalvis, while to Mirbel is 
to be credited the synonym Frenela Fontanesii. Spach takes it 
as the type of the genus Callitris in spite of its North-African 
origin, and Bentham makes it the representative of a section of 
the genus Callitris under the sectional name Tetraclinis. 
Tetraclinis articulata, as we prefer to call it, has the articulate 
stems of Callitris, but differs in its flattened (not triangular), 
divaricate, Salicornia-like branches, its four-ranked, uniform 
foliage, and its solitary female cones consisting of four nearly equal 
decussate or pseudo-verticillate scales, at first somewhat fleshy, 
and with two equally winged, erect seeds to each scale. Traces 
of this bract are visible near to the apex of each scale. The 
