522 The American Naturalist. [June, 
blocks or boulders, that are different in character from the blocks and 
boulders found in the glacial drift of the district. König’ has recently 
described those occurring in the schists near Stockerau as micro-gran- 
ites, granophyres, granites, gneisses and mica schists, but has not suc- 
ceeded in tracing them to their origin. 
The Eleolite-Syenite of the Serra Monchique.—Kraatz,’ 
Koschlau and Hackman give a very thorough account of the well 
known eleolite-syenites of the Serra Monchique, Portugal... Two prin- 
cipal types of the rock are distinguished. One is the coarse grained 
type from Picota and the other a finer grained type from Foia. These 
are crossed by streaks (Schlieren) of fine grained rock, and in them are 
basic concretions. The eleolite-syenite has produced marked contact 
effects in the surrounding sedimentaries and has suffered corresponding 
changes on the periphery of its mass. A system of dykes cutting the 
syenite comprises bostonite-porphyry, leucite-tinguaite, vitrophyre, 
eegirine-tinguaites, eleolite-syenite porphry, camptonitic-tinguaites, 
nepheline-tephrite, monochiquite and camptonite. 
The Picota rock may be a deeper facies than the Foia rock. It con- 
sists essentially of eleolite and feldspar, with a few dark colored com- 
ponents forming a granitic or atrachytic aggregate. The dark colored 
components are diopside, often with an ægirine or an sgirine-augite 
border, sphene, biotite and lavenite. Except the first named they are 
all in small quantity. Analyses show the presence of 37.44% soda- 
orthoclase, 24.34% albite, 14.43% nepheline, 11.6% augite, 10.21% 
lepidomelane and .22% sphene. The Foia rock differs from the Picota 
type in the presence of but a small quantity of nepheline and in its 
finer grain. In some of its varieties it resembles strongly the pulaskite 
of Arkansas both in appearance and in composition. An analysis 0 
the Portugese rock yielded : 
a TiO, Al,O, Fe,O, FeO MnO MgO CaO K,O Na,O-H,O Total 
60.4 19.23 .63 3.19 .67 1.73 6.88 6.99 1.74 = 101.48 
Near the village of Monchique a pegmatitic pulaskite or eleolite-sye 
nite was met with, the only instance of a pegmatite discovered in the 
district. 
The streaks (Schlieren) i in the Picota rock are more acid than the 
body of the rock, one in the Foia area contains a hornblende of the 
katophorite-arfvedsonite series, otherwise they present no unusual feat 
ures. 
age u. none Mitth., XV, p. 109. 
*Ib., 
