1068 The American Naturalist. [November, 
and robust. Its inferior border is nearly straight to below the second 
root of the first tubercular. It is there strongly curved upwards, in a 
regular convex outline. There are two mental foramina, one below 
the second, the other below the third premolars. The alveolus of the 
external incisor is large, and is directly in front of the canine. The 
symphysis extends posteriorly to the middle of the pm. iii. 
Measurements.—Length of dental series, inclusive of canine (in a 
straight line), 73 mm.; of premolar series, 30 mm.; of sectorial, 19 
mm.; of base of m à, 10 mm.; of alveolus of m 3, 5.5 mm.; length of 
heel of sectorial, 6 mm.; width of do., 6 mm. Depth of ramus at 
pm. iv., 15 mm.; at front of m2, 18 mm. 
From the Loup Fork Miocene of Nebraska. 
In illustration of the general characters of the genus Aelurodon, I . 
give a restoration of the skeleton of the Ae. sevus Leidy, from a 
mounted specimen in my collection. The shaded parts represent the 
bones in my possession. —E. D. Cope. 
On Dendrophycus triassicus Newb.—In the last number of 
the NATURALIST is a paper on ** Variation," by Professor Joseph F. 
James. Much of the matter of that paper is interesting and valuable; 
but there is one paragraph, on page 1080, to which.I decidedly object. 
It does injustice to me and discredit to the author. The passage is as 
ollows : 
* Even in one of the latest monographs published by the U. S. 
Geological Survey (Vol. XIV.) we observe an inorganic marking (as 
it appears to us) masquerading under the name of a sea-weed ; an 
under a new name, too, because its brother rill-mark existed some 
geological ages prior to its own oncoming formations." 
This paragraph must refer to my Dendrophycus triassicus, since there 
is no other sea-weed described in the volume, and I remark upon the 
resemblance which this bears to Dendrophycus desorii Lesq., from the 
Pottsville red shale (Lower Carboniferous). 
ow, as Mr. James has probably never seen a specimen of the plant 
I described, and certainly has never seen the type specimens, he seems 
to me hardly qualified to express an opinion upon the subject. Besides 
that, there can be no question that Dendrophycus triassicus is & plant, 
and not arill-mark. I have been for half a century studying rocks 
and fossils in the field, and have given special attention to fossil plants ; 
hence I ought to be qualified to decide whether the impression 1 
question is of mechanical or organic origin. 
Iam familiar with the discussion which has taken place between 
Dr. Nathorst and the Marquis de Saporta about fossil algz, tracks, and 
Re ar ^ o, ue er rdg Wo: 12 y ILL ep NER E EAR 
