184 



SCIENCE 



[N. S. Vol. XXV. No. 631 



THE NEW YORK ACADEMY OF SCIENCES 

 SECTION OF GEOLOGY AND MINERALOGY 



At the meeting of December 10, 1906, the 

 following papers were presented: 



Present Structural Character and Prolahle 



Former Extent of the Palisade Trap: 



Alexis A. Julien. 



In the Palisades, the trap sheet along the 

 lower Hudson Eiver, the structures most gen- 

 erally known are the vertical or columnar and 

 the coarsely bedded structure with foliation 

 parallel to that of the whole stratum. Less 

 familiar is a coarse concentric structure vis^ 

 ible on horizontal surfaces. A thinly lamellar 

 structure has also been brought out by natural 

 etching on weathered vertical surfaces, which 

 appears to represent a flow structure, or, per- 

 haps more properly, a pressure lamination. 



At a certain zone along the face of the es- 

 carpment an interrupted or continuous sheet 

 of decayed rock crops out, a principal cause 

 of destruction of the columns by undermining. 

 It indicates a process of preglacial decay of 

 extreme antiquity, and is attributed to a bal- 

 ance of conditions of perpetual moisture in a 

 coarsely granulated band of the trap. Two 

 systems of faults traverse the trap sheet from 

 north, or a little east of north, to the opposite 

 point, and from north-northwest to south- 

 southeast. Eight or nine faults have been 

 located by previous observers, and some of 

 these extend for several miles. But there is 

 abundant evidence of a large number of other 

 faults, those of one system marked by depres- 

 sions which furrow the top of the ridge in the 

 direction of its trend; those of the other sys- 

 tem indicated by nicks or clefts (cloves) along 

 the edge of the escarpment. The original 

 thickness of the trap sheet shows that these 

 hollows represent the bottoms of ancient 

 gorges of a drainage system guided by the 

 faults over the summit of the ridge. This 

 signifies an enormous amount of denudation, 

 doubtless effected by the continental glacier, 

 which, in eonnectibri with the faults, has 

 also resulted in the southwestward slope of 

 the ridge down to the sea-level. As to 

 the mooted question of the eastward exten- 

 sion of this sheet of the Newark formation 



beyond the Hudson Eiver, direct evidence ap- 

 pears in the low rock terraces between Dobb's 

 Ferry and Peekskill, formerly occupied by the 

 overlap of this formation; in the common dis- 

 tribution of zeolites, etc., in cracks of the 

 gneisses on the east side of the river, which 

 could only have been derived through infiltra- 

 tion of thermal waters from an overlying trap 

 sheet; and in the correlation of depressions 

 on opposite sides of the river, which have been 

 impressed by an ancient drainage system over 

 the uplifted Mesozoic terrane and across the 

 present line of the Hudson Eiver. 



Development of the Inner Wall in Paleozoic 



Corals: G. E. Anderson. 



From serial sections of Craspedophyllum 

 subcmspitosum it was shown that the primi- 

 tive union of septa is retained even after 

 radial condition of septa is reached. The 

 wall is formed by the turned-over and fused 

 ends of the septa and at one stage resembles 

 the fossular wall of certain corals. Final 

 closure of the wall by bridging of the fossular 

 gap occurs in accelerated mutations of this 

 type and is normal in Eridophyllum. No true 

 inner wall exists in Acervularia and similar 

 genera. 



The Geographical Classification of Marine 



Life Districts: A. W. Geabau. 



After a discussion of principles the follow- 

 ing tentative classification was outlined: 



GEOGRAPHIC DIVISIONS 



I. Intercontinental seas /Littoral, pelagic, abyssope- 

 or oceans. 1 lagic, abyssal. 



II. Intracontlnental seas. 



6. Epicontinental s 



/Littoral, pelagic, abyssope- 

 t lagic, abyssal. 



-{ Littoral, pelagic. 



III. Continental | [seas or / Littoral, pelagic, more rarely 

 lakes. I abyssal. 



The speaker advocated that the term littoral 

 be extended so as to cover all that district 

 from high water to the edge of the continental 

 shelf (or beyond, to the point where the 

 photic or lighted portion of the sea bottom, 

 ends), instead of restricting it to the shore 

 zone, as is often done. He also advocated 

 the restriction of the term epicontinental sea 

 to that type of intracontlnental sea which has 

 no abyssal district. The advantage in pre- 



