264 The American Geologist. April, 1892° 
rodira cannot be placed near the sturgeons on account of the structure of 
the pectoral fins, and the cranial structure which has no resemblance to 
that of those fishes. F 
Part IV. In this part is described the first known specimen cf the 
pectoral spine, almost complete, of Holonema rugosa Clay pole, from Mans- 
field, Tioga Co., Pennsylvania. The spine is without complete segmen- 
tation, differing in this respect from Bothriolepis and Pterichthys. The 
spine is continuous to the apex, thereby constituting a generic distinc- 
tion between Holonema and Bothriolepis. Length 54 mm, base width 11 
mm, middle 7 mm. 
Part V. Onthe Paired Fins of Megalichthys niiidus Cope. In this paper, 
the author, after announcing the provisional withdrawal of his genus 
Ectosteorhachis (Megalichthys) (Proc. Am. Phil. Soc.,1880,p 56) gives 
a study of the paired limbs and concludes that it is probably intermediate 
between Ceratodus and Pterichthys and possibly Arthrodira. The limb 
structure does not resemble either Polypterus or Ceratodus. 
Part VI. On the Non-Actinopterygiun Teleostomi. This is practically 
the same paper which appeared in the Am. Nat., 25 May, 1891, pp. 479- 
481. 
In Part VII the author describes two new species of Platysomid, P. 
palmaris from the Permian of 8. Indian Territory and P. lacoviéanus from 
the Coal Measures of Mazon Creek, IIl. 
Stratigraphy of the Bituminous Coal Field of Pennsylvania, Ohio, and 
West Virginia. By IsraEL C. WHITE. pp. 212; with a folded map, 10 
other plates, and 152 figures of sections in the text. (Bulletin No. 65, 
U.S. Geological Survey, 1891. Price, 20 cents.) 
The classification adopted in this report partly preserves the subdivis- 
ions and nomenclature of the Brothers W. B. and H. D. Rogers, adding 
thereto such new features as now seem necessary from the present 
wider and more detailed knowledge of the coal-bearing strata. The en- 
tire Carboniferous system of the Appalachian region comprises three 
grand divisions, founded on the conditions of their deposition. The 
lower division is exclusively marine; the middle division consists of 
shore deposits, interrupted by incursions of the sea, and includes the 
lower Coal Measures; and the upper division embraces only fresh and 
brackish water deposits, including the upper Coal Measures and the 
Permo-Carboniferous series of Dunkard creek. Professor White here 
describes the outcrops and stratigraphy of the five series into which the 
Upper and Middle Ca’boniferous are subdivided. Many interesting 
questions in connection with this work are reserved for discussion when 
the remaining southern half of the Appalachian coal field shall have 
been more fully studied. 
On a group of volcante rocks from the Tewan Mountains, New Mexico, and 
on the occurrence of primary quartz in certain basalts. By Josern P. Ip- 
DINGS. pp. 34 (Bulletin No. 66, U. 8. Geol. Survey, 1890. Price 5 cents.) 
The volcanic series of the Tewan mountains shows a gradual transition 
trom rhyolites through andesitic rocks to basalts, ranging thus from one 
