596 RECORD OF MEETINGS OF THE 



Mr. Gordon stated that J. E. Duerden, in the Johns Hopkins 

 University Circular for 1902, has endeavored to show by studies 

 based on Lophophyllum proliferum that the Rugosa exhibit 

 a hexameral plan of growth of the primary septa, in so far as 

 L. proliferum. may be taken as representative. Certain studies 

 on Streptelasma prof nudum show a primary tetrameral plan. 

 The fact that 5. profundum is a middle Ordovicic type indicates 

 that this is the primitive condition. Moreover, a careful exam- 

 ination of Duerden 's figures shows that they lend themselves 

 to an entirely different interpretation from that which Duerden 

 gives. This interpretation is that two of the so-called primary 

 septa are secondary septa precociously developed; that their 

 sequence and ultimate position are the same as those for the 

 secondary septa which appear in the corresponding positions 

 in the corresponding quadrants of a Zaphrentoid coral; that 

 the fossula and cardinal septum are on the concave side of the 

 corallum; and that if Duerden's figures be inverted they reveal 

 a perfect similarity to a Zaphrentoid coral, as far as the order 

 of appearance and the arrangement of the septa are concerned. 



The fact that L. proliferum is a Carbonic type indicates that 

 it is a modified type of the Zaphrentoid coral, the first secondary 

 septa appearing in nepionic stages and thus simulating the 

 character of primary septa. 



Mr. Brown stated that a few years ago, while studying the 

 Cretacic deposits of Long Island, Block Island, and Martha's 

 Vineyard. Dr. Hollick of the New York Botanical Garden made 

 a collection of fossil molluscs and plants from Chappaquid- 

 dick Island. The fossil molluscs were deposited in the Colum- 

 bia University collection without being fully and carefully 

 studied. 



These fossils occur in the island in ferruginous concretions. 

 They seem to have been deposited somewhere to the north of 

 where they are now found, then moved as glacial drift, re- 

 assorted and deposited in their present position. From their 

 lithological similarity to concretions containing undoubted 

 Cretacic fossils found elsewhere on Martha's Vineyard, Dr. 

 Hollick thought that these concretions and their contained fos- 

 sils must be of Cretacic age. 



