Editorial Comment. 321 
HYPOTEMNODON, gen. nov. 
Talon of inferior sectorial trenchant : internal cingulum 
greater and more pronounced than in Temnocyori. Inferior 
molar 2 tubercular, with internal cks])s equalling in size those 
of the external side. 
H. coryph.eus Cope (Temnocyon coryphmus Cope). From 
the above it seems necessary to remove Cope's species, T. 
coryphceus (Tert. Vert., vol. in, book i, pp. 906-912) from the 
genus Temnocyon and to erect a new genus to which is given 
the name Hypotemnodon. The specimen under considera- 
tion is the left ramus, collected by Dr. J. L. AVortman in the 
John Day "bad lands" and described by Prof. Cope in his 
Tertiary Vertebrata under the genus Temnocyon. 
The above new species and new genus will be described 
more fully in a memoir now in course of preparation. 
EDITORIAL COMMENT. 
THE ORIGIN OF SPHEROIDAL BASALT. 
The eruptive rocks of Point Bonita . F. Leslie Ransome. 
(Bulletin of the Department of Geology, University of CaL, 
vol. 1, pp. 71-114, Dec, 1893.) 
The author presents a map of the region, which is the pe- 
ninsula and point which, on the north, shut in a part of San 
Francisco bay and terminate on the north side of the "golden 
gate." The most of this area consists of the San Fran- 
cisco sandstone, but along the western edge the country rises 
abruptly from the Pacific ocean, this elevation consisting of 
a ridge of basic eruptive rocks. These are terminated toward 
the east by a supposed fault which runs north and south but 
a short distance east of the ridge of eruptive rock. The ridge 
descends toward the north, ceasing at about four-fifths of a 
mile from the "golden gate." 
The eruptive rocks show three facies in the field, which are 
also equall}' evident in making a microscopic examination. 
The author enumerates spheroidal basalt, pyroclastic rock and 
diabase. In a section through these parts the diabase is 
shown as rising highest, and as intrusive through the others, 
