568 PROCEEDINGS OF MEW YORK MEETING. 



!/■;. medio-plieata. Begins in the Oriskany. 



n) Forms of sub-circular or elongate outline — S. hungcrfordi. 

 Forms in which plications are few and strong -S. keokuk. 

 Forms in which plications are in fascich S. camerata. 



I S ringothyris group. Begins in the Corniferous. 



The radiata, fimbriate, and medio-plicaia are without «.——•• 1 1 1 i : 1 1 variation 



in spiriferoid character. 

 Icevis: slightly variable in development of dental lamellae. 

 lamtllosa: septate or non-septate. The septate group begins in the 

 Niagara, is continued through the lower Helderberg, Cornifer 

 Hamilton and Kinderhook ; the Bhell remaining impunctate 

 Results in Spiriferina. 

 Where does punctation begin ? 

 medio-la via : Gradual dr\ elopmenl of apical callosity, Syringothyria tube, 

 high area, etc. 



Homologous structure in Cyrtina. 

 Incipient punctation in Syringothyria. 

 Cyrtina: In external expression usually in harmony with medvo-lcevis. 

 > Like Cyrtina on outside ; differs from Spirifera only i:: the de- 



velopment of the dental lamella). 



The next paper was entitled : 



<»N ill i : METAMORPHIC ROCKS OF SOUTHEASTERN NEW YORK. 



nv B\ .1. li. MERRILL. 



Ii led to a discussion in which ('. If. Van Hise, B. K. Emerson, C. II. 

 Hitchcock, and J. E. Wolff took part. 

 The remaining paper was read by title, in the absence of the author: 



ON POT-HOLES NORTH OF LAKE SUPERIOR UNCONNECTED WITH EXISTING 



STREAMS. 



BY PETER MCE ELL \ K. I'. <;. B. 



In is;i inv brother Donald McKellar discovered a large pot-hole in hornblende 

 rock about I' miles back from McKellar harbor, northeast of the Slate islands, on 

 il P - north shore of Lake Superior. 



I examined the locality and found aboul fifty similar holes, with diameters varj ing 



from :i couple of feet up to i 'e than thirty feet. Some are quite round, Bmooth, and 



well denned ; others are oblong, - f which appear to result from coalescence of 



two or more holes. These holes occur on i li'- east side of a steep mountain, and show 



on tin' different ledges from the bottom up t" within a few feel of the summit. The 



moil ii i ain ~id'- •■!' many of the boles Btands up above the front Bide, in Borne 



• much as thirty feet or more. In general these holes are filled up, or nearly 



with such materials n- bowlders, gravel, sand, black mink and water, but Borne are 



emptj down for many feet. Their depths are unknown, as in uo case has tli*' bottom 



n reached or exposed, although in several instanci - a pole has been Bboved 



down in the j ••■:it \- l"'tt.>nj for several feet, 



