452 PROCEEDINGS OF THE ACADEMY OF [Aug.,. 



1,300 feet contours about 1| miles southeast of Joshua and 

 some nine miles from Staghorn Point in a northeasterly direc- 

 As this line corresponds quite closely to the general direction 

 of dip of the Hamilton shales, the difference in altitude in no way 

 precludes the stratigraphic equivalency of the Joshua and Staghorn 

 Point beds. Though the horizontal exposure is very limited at the 

 Joshua locality, we are furnished with quite an extensive vertical 

 section. Enough is revealed to allow us to say that here we have 

 an upper reef some 65 feet thick separated by barren shales from one 

 or more thinner reefs. 



Allowing, then, essential contemporaneity for the Onondaga County 

 coral masses already mentioned, it is well in passing to say that 

 other coral-bearing localities to the east of Vesper and Joshua have 

 not yet been visited, while to the west of Staghorn Point the absence 

 of definite reefs in the Skaneateles Valley renders Luther's suggestion 

 of correlation with the "Encrinal band" still an open question. 



The- Coral-bearing Drift of the Otisco Valley. — Along the eastern 

 side of the Otisco Valley exposures of the bed rock are, on the whole, 

 quite rare. So far none of the exposures examined have shown 

 coral beds in situ. The glacial drift, on the other hand, is very high 

 in cyathophylloid corals. 



The ultimate source of drift inclusions is always open to some 

 question, but in the present case the corals, besides being specifically 

 identical with those of the Hamilton reefs, are also of the same 

 general size and in many cases carry adherent fragments of the 

 Hamilton matrix. 10 After the examination of a large number of 

 specimens the author believes that no reasonable doubt can exist 

 as to the origin of these fossils. 



In places the drift is so packed with corals as to preclude the 

 theory of transportation for any considerable distance. Every- 

 thing, in fact, points to a very local source, and unless we ascribe 

 this to the Joshua reefs alone, it is believed that we are warranted 

 in assuming the presence of extensive though drift-covered Hamilton 

 reefs along the eastern wall of the Otisco Valley. Though the 

 exact horizon of such hypothetical reefs must, of course, remain 

 in doubt, the probabilities are that it coincides quite closely with the 

 horizon of those Hamilton reefs which we can see in place. 



In view of the great number of corals in the local Onondaga limestone, 



and in view of the fact that the Hamilton species are also found in the limestone, 



night be urged that some of this is Onondaga drift. The Hamilton reefs are, 



, made up almost entirely of Zaphrentis, Heliophyllum, and Cystiphyllum, 



)nondaga contains not only many additional genera of corals, but an 



associated Brachiopods, Bryozoa, Crinoid stems, etc. These 



s have not been found in the Otisco Valley drift. 



