806 The American Naturalist. [September 
Cambridge, Somerville and Jamaica Plain. The titles are given and 
with each title are index letters indicating in which library the period- 
ical may be found. Numerous cross references add to the value of the 
list, which, while intended for students in the neighborhood of Boston, 
will prove of great value to investigators in any locality. 
In this connection we might call attention to the fact that the Boston 
Society of Natural History published,’ a few years ago a list ot serial 
publications currently received in its library and that it has now issued 
a supplement to this list as well as a list of discontinued serial publica- 
tions in its library® of about four hundred titles. 
General Notes. 
PETROGRAPHY? 
Igneous Rocks of Trans-Pecos, Texas.—The igneous rocks 
intrusive in the sedimentary series of Trans-Pecos, Texas, according to 
Osaun’ comprise plutonic, dyke and effusive types belonging toa series 
of rocks rich in soda. They are characterized by the possession of al- 
kaline pyroxenes and amphiboles (aegirine, aegirine-augite and arfved- 
sonite), of microperthitic intergrowths of orthoclase and albite, and of 
riebeckite, lavenite and a mineral resembling ainigmatite. In the 
Apache Mountains the plutonic rocks are accompanied by dykes of 
paisanite, tinguaite and bostonite. The intrusive phases of this series 
are eleolite-syenites, normal and porphyritic varieties, aegirine-syenites 
and normal syenites. The dyke rocks identified are tinguaite, boston- 
ite, paisanite, (see analysis I, below), and the effusives are rhyolites and 
phonolites. Several of these rocks have been noticed in the reports of 
the Texas Geological Survey. The paisanite is regarded as & quartz 
bearing member of the gromdite-tinguaite series as found in the neigh- 
borhood of Christiana. The Texan phonolite is of such a peculiar typé 
that it has been designated as apachite. It occurs in two laccolites 20° — 
in sheet form. The rock is composed of phenocrysts of sanidine and 
nepheline, the latter often surrounded by rims of amphiboloids 10 & 
> Proceedings of the Boston Society of Natural History. Vol. XXVI, 1894 
ê Proceedings, vol. XX VIII, 1897. ; 
1 Edited by Dr. W. S. Bayley, Colby University, Waterville, Me. 
? Min. u. Petrog. Mitth., XV, p. 394. 
3 Cf. AMERICAN NATURALIST, 1894, p. 514. 
