SCIENCE. 



3 



The well is six inches in diameter, and sufficient water 

 was obtained to make it a success. 



The other well is at the pump-house of Bischoff's 

 Brewery, some 500 feet east of the most eastern serpen- 

 tine outcrop at the foot of the hills. This has now ( Dec. 

 1st) reached a total depth of 210 feet, and the boring is 

 still unfinished. The section thus far has been as follows : 



Glacial drift 80 feet. 



Various kinds of tough hornblende schist, 



apparently varying to serpentine,. . ..130 feet. 



As yet no gneiss nor granite has been reached. 

 An outcrop of clay occurs near Clifton, about three- 

 fourths of a mile south of the Forts, near the southern 

 edge of the terminal moraine ; it has been found, by bor- 

 ings made by Mr. Charles Townsend, in excavations for 

 cellars, to be at least ten feet in thickness, and of a light 

 color. 



The clay is probably of Cretaceous age, and if so, this 

 is the most eastern point at which beds of that age are 

 known on Staten Island. 



Mr. W. T. Davis has recently observed a large fossili- 

 ferous boulder of Schoharie Grit on the shore at Brighton 

 Point. The fossils have been submitted to Dr. Newberry, 

 and the following species identified -.—Dalmanites anchi- 

 ops ; Orthoceras Pelops, Strophodonta hemispherica ; 

 Atrypa reticularis ; Strophomena rhomboidalis ; a Fene- 

 slella ; and Zaphrentis prolifera. 



Glacial groovings have recently been noticed on the 

 hornblende-rock, which is exposed at tide-level on 

 Brighton Point. Some of the grooves are at least one- 

 quarter of an inch in depth, three inches wide and four 

 feet long. Their bearing varies from N. 15° W. to N. 

 17° W. 



Discussion. 



Prof. D. S. Martin considered the specimen of so- 

 called hornblende schist from the well-boring, not to con- 

 sist properly of that rock, but to be partly hydrated — 

 apparently a less altered condition of the rock which 

 higher up gives us the soft, semi-fibrous serpentine of the 

 island. 



Dr. Newberry regarded the serpentine of Staten 

 Island as probably a pseudomorphcus condition of horn- 

 blende slate. It differs considerably from the mottled 

 serpentine of New York Island, which is '• verde antique "; 

 that is, is composed partly of serpentine and partly of 

 carbonate of lime, and is scarcely distinguishable from 

 the Moriah marble, which is quarried at Moriah, Thur- 

 man, etc., in the Adirondack region. It is a peculiar 

 rock, and one of the connecting links between the rocks 

 of New York Island and those of northern New York and 

 Canada. Taken together, these afford strong indications 

 of the Laurentian age of the New York Island and Staten 

 Island crystalline rocks. 



Dr. Newberry further said that the accurate determina- 

 tion of the age of the rocks of New York Island, of Staten 

 Island, and of those underlying the drift of Long Island, 

 was in the highest degree desirable and important ; and 

 while he was satisfied that the former were Laurentian, 

 and the latter Cretaceous, it was eminently desirable that 

 unquestionable proof should be found of this, if it is true. 

 At present no positive assertions could be made, and the 

 duty devolves on the geological members^of the Academy 

 to rid the subject of doubt. 



The fossils in the boulder referred to by Mr. Britton 

 prove to have come from the Schoharie Grit. In its orig- 

 inal condition this was a hard, compact blue limestone, 

 but is here presented in a leached state, by the passage 

 of water's containing carbonic acid, with a loss of its lime, 

 color, and density. It was derived from northern New 

 Jersey, to which locality a belt of this rock runs down 

 from Schoharie county. Its transit by ice was effected 

 • without doubt through the valley of the Hackensack, 



which lies east of the Orange Mountains and west of the 

 Palisades. This glacial movement is indicated by the 

 direction of the stria; observed by Mr. Britton, as well as 

 by those in the Hackensack valley. 



Mr. A. A. Julien recalled the results of his lithologi- 

 cal examination of the serpentines both of Staten Island 

 and of Hoboken, presented before the Academy two years 

 ago, in which it was shown that sections of all these 

 rocks abounded in minute fragments of more or less 

 altered amphibole. The conclusion then stated, that 

 these serpentines must be certainly derived from horn- 

 blende schist, was confirmed by the interesting discovery 

 of the latter rock, both in well-boring and on Brighton 

 Point. Serpentines of the same general character and 

 origin occur frequently throughout New York and West- 

 chester counties. The mineral serpentine is also found 

 in small quantity as a vein-deposit, not pseudomorphous, 

 like the main mass, but presenting an amorphous mate- 

 rial with banded vein-structure, associated with mag- 

 nesite, dolomite, etc.; e. g., the marmolite of Staten Island, 

 a translucent green variety found at Hoboken, and also 

 at West 60th street on New York Island, etc. At all 

 these localities the amphibole survives in a more or less 

 altered condition ; e. g., the tremolitic talc schists and 

 slaty tremolitic serpentines of Staten Island and Hoboken, 

 the hydrous anthophyllyte and unaltered tremolyte rock 

 of West 60th street, New York, the tremolitic amphibo- 

 lyte of New Rochelle and Rye, in Westchester county, 

 etc. 



Mr. Britton confirmed the last remarks, by the state- 

 ment that a vein of material, strongly resembling the 

 hydrous anthophyllyte of New York, had been struck at 

 the bottom of one of the wells on Staten Island ; also 

 that veins of mixed serpentine and calcite were observed 

 at Stapleton, possessing a banded structure parallel to 

 their walls. At that point the apparent thickness of the 

 serpentine bed is 150 feet, but the crest of the hill is com- 

 posed of talcose schist. 



Mr. W. Le Conte Stevens then read a paper on 

 "The Mammoth Cave of Kentucky," 



He also exhibited specimens of the blind fish {Amblyopsis 

 spelaeus), and blind crawfish {Cambarus pellucidus), 

 and stereoscopic views of various points in the interior of 

 the cave. 



(Abstract.) 



At the close of the Cincinnati meeting of the American 

 Association for the Advancement of Science, in August 

 last, he was one of a party of seventy-five members who 

 visited the Mammoth Cave, remaining there two days, 

 during which the greater part of the time was spent in 

 exploration. He made no claim to new discoveries, 

 but wished to call the attention of the Academy especially 

 to recent observations, for the most part by Rev. H. C. 

 Hovey, of New Haven, in regard to the temperature and 

 structure of the cave. Mr. Hovey read a paper on this 

 subject in Cincinnati, only a brief abstract of which has 

 yet appeared in print, making use of a map, which is the 

 first of its kind ever exhibited. The strictest precautions 

 are observed by the authorities controlling the cave 

 to prevent visitors from taking surveying instruments in 

 with them : but the present manager, Mr. Francis Klett, 

 has made a careful survey of the most interesting parts, 

 and in time this will probably be given to the public, 

 though possibly the scale of measurement may be with- 

 held. 



The central and right-hand portions of the map ex- 

 hibited by Mr. Stevens had been enlarged by him from a 

 copy of Mr. Klett's map. The left-hand portion was 

 drawn only from recollection of the localities traversed, 

 and not to scale, being intended only to illustrate princi- 

 ples. The same remark applies to the vertical projection, 

 the lettering of which corresponds with that of the hori- 

 zontal projection. 



The temperature observations of Mr. Hovey were con- 



