136 • PROCEEDINGS OF THE ACADEMY OF [1889. 



Nat. Hist. IV. 85. In a notice of that search given in the Proceedings 

 of the Academy for 1869, p. 91, Mr. Redfield had said, " If the Corema 

 is again to be discovered in New Jersey it will probably be in the 

 wide sandy waste a few miles west of Cedar Bridge, near the bound- 

 ary between Burlington and Ocean Counties, where a succession of 

 elevated ancient beaches offers conditions similar to those of Cape 

 Cod." He had now the satisfaction to report that about two years 

 ago the plant was discovered by Prof. Merrill of Columbia College, 

 N. Y., in the precise region which had been indicated. The place 

 was soon after visited by Prof. Britton, and in April of this 

 year, at the invitation of the latter, Mr. Arthur Hollick, Dr. J. B. 

 Brinton and Mr. Redfield had accompanied him in a visit to the local- 

 ity which lies about three miles west of Cedar Bridge, and about eleven 

 miles west of Barnegat. The region is most singular in its aspect and 

 impresses one with a sense of desolate loneliness. Forming the 

 divide or water-shed, it rises in gentle swells which command an 

 extensive view of a sandy desert leached by the rains to a degree 

 of barrenness such that the scattered trees of Pinus rigida can attain 

 the height of only three or four feet. The party was surprised 

 at the amazing extent of Corema, exceeding that of any locality 

 yet reported in the United States, being more or less abundant over 

 a tract nearly a square mile in extent, its scattered patches in some 

 places becoming confluent over large spaces. Myriads of young 

 seedlings were also springing up in the bare white sand, so that there 

 is little prospect of the plant becoming extinct. This is now the 

 most southern station known for Corema, and was probably the 

 origin of the few patches which Dr. Torrey found at Cedar Bridge, in 

 1834, but which had disappeared before 1869. 



The following communications were made in connection with the 

 proceedings of the Conchological Section : 



The Radula in Rhipidoglossate Mollusks.- — Mr. H. A. Pilsbry 

 spoke of the modes of specialization of the radula in rhipidoglossate 

 mollusks illustrating his remarks by black-board diagrams. He stated 

 that the marginal teeth undergo but slight variations throughout the 

 group. The reduction in number of the teeth consequent upon the 

 enlargement of the individual teeth takes place in the median por- 

 tion of the membrane, where differentiation of the primitive homo- 

 dont radula commenced. In the family Trochidre the outer lateral 

 teeth (next to the numerous undifferentiated marginal teeth) become 

 degenerate in the more specialized forms (Trochus, Clanculus, etc.) 

 which have only five perfect laterals, a sixth being represented by a 

 small plate without cusp or cutting point. In certain other genera of 

 Trochids, there are seven or more laterals. In Turbinidse and 

 Phasianellinre, on the other hand, the reduction in number of the 

 teeth proceeds by the obsolescence or total loss of the central tooth 

 (as in the group of Phasianelhe which the speaker had named 

 Orthomesus), or the loss of the cusp of the tooth, as in certain 



