! ;" Biographical Sketch of Elkanah Billings. — Ami. 281 
4. Notes on the structure of the Crinoidea, Cystidea and Blas- 
toidea. pp. 90-128. 
5. On some of the Fossils of the Arisaig series of rocks. Upper 
Silurian Nova Scotia, pp. 129-144. 
(Note on fotsils from Ballinac Islands, British Columbia. Geol. Sur. 
Can., Rep. Progress, 1873-74. p. 98. Montreal. Published 1874. 
On some new Genera and Species of Palseozoic Mollusca. Can. Nat. ^ 
'^uart. Journ. Sc, vol. 7, No. 5, pp. 301-302. (Genera Ilionia and. 
Pterinotella) — July, 1874. Montreal. 
On some new or little known fossils from the Silurian and Devonian 
Rocks of Ontario. Can. Nat. & Quart. Journ. Sc, vol. vii. No. 4. 
pp. 230-240. 
1876, 
(List of Devonian Fossils prepared by E. Billings included on page 68 
of "Report on the Country between the Assiniboine river and lakes 
Winnipegosis and Manitoba," by J. W. Spencer.) Geol. Sur. Can., 
Rep. Progr., 1874-7.S, issued Montreal, 1876. 
On the Structure of Obolella chromatica. Amer. Journ. Sc, Ser. 3, 
Vol. XT, pp. 176-178. New Haven, Conn., U. S. A. 
ORIGINAL MICACEOUS CROSS-BANDING OF 
STRATA BY CURRENT ACTION. 
By J. B. WooDWORTH, Cambridge, Mass. 
The process of sedimentation normally produces layers of 
uniform texture parallel with the surfaces of the laminae. 
Bands of different mineralogical and textural characters in- 
clined to the planes of stratification are common in the meta- 
morphic rocks as the result of mineralization of shear zones or 
of the brecciation and mineralization of shear zones inclined 
to the original sedimentation planes. The following descrip- 
tion relates to a case in which a micaceous banding occurs as 
an original structure at a high angle with the stratification 
imitating the dual structure of some metamorphosed sediments. 
The Fitchburg railroad one and a half miles east of Con- 
cord, Mass., occupies a deep cut through a rude glacial sand- 
plain which encloses lake Walden. In a side cutting in this 
excavation, the writer observed in 1898 a bed of fine, brown 
glacial sand about one foot thick sharply demarcated from 
clays and sands above and below by certain peculiarities of 
structure and texture. This layer was very regularlv beset bv 
current-mark with westward facing steeper fronts, indicating 
the drifting of the sediment in that direction during deposition. 
The crests of the ridges were regularly superposed, each suc- 
cessive layer having its crests at regular intervals somewhat 
