1890.] Geology and Paleontology. 1069 
trail-marks, and I know how dogmatically Mr. James has written on 
the so-called sea-weeds of the Cincinnati group; and yet I can see no 
reason for doubting that Dendrophycus is organic, and no excuse for 
the confidence with which Mr. James pronounces an opinion upon a 
subject of which he really knows nothing. Nobody doubts the organic 
character of Spirophyton ; but no one can compare Dendrophycus with 
the various species of Spirophyton which occur in the Cauda-galli grit, 
and thence upward into the Coal Measures, without seeing that they 
must go together. Still further, no one can compare good specimens 
of Dendrophycus—those showing the extremities of the fronds—with 
sea-weeds of the genus Desmarestia without finding so much in common 
as to be convinced that they are nearly related. This similarity was 
remarked by Professor Balfour, to whom the plant of the Umbral 
shales was referred by Professor Rogers. We find in both the same 
cylindrical, firm, hard and smooth stems, dichotomously, forked, be- 
coming at their extremities wire-like, and terminating in slender, acute 
points. In Dendrophycus, as in Desmarestia, many of these terminal 
branches are set with lateral, acute, alternate thorns. Any one who 
will examine she specimen, part of which is figured in Monograph XIV., 
U. S. Geological Survey, Pl. xxı., Fig. 2, will, I think, regard the 
theory that it is a rill-mark as untenable. To all those who have been 
led to such a conjecture by the imperfection of the figures given, or 
the positive tone of Mr. James’s paragraph, I can only say, examine 
the specimens and that idea will be no longer entertained. 
In order to get all the light possible on this subject, I sent some 
specimens of Dendrophycus and Spirophyton to Professor W. G. 
Farlow, of Cambridge, our highest authority in all that pertains to the 
algze ; he kindly gave me the result of his examination of these speci- 
mens in a letter of considerable length, in which he expresses the 
opinion that they are organic and not of mechanical origin, and that 
they are the remains of sea-weeds. Had Mr. James waited until he 
could have seen the specimens of Dendrophycus, I venture to say he 
would never have given expression to the dogmatic and even con- 
temptuous opinion which is contained in the paragraph I have quoted. 
J. S. NEWBERRY. 
New York, Nov. 7th, 1890. 
