242 The American Naturalist. [March, 



erroneous correlations resulting from the use of Seolithvt, but they are 

 numerous enough. 



The second objection urged will probably be the multiplication (A 

 names resulting. Some will, perhaps, prefer to let Scolithus linearis 

 do duty for all the forms if they can be shown to be indistinguishable, 

 but this objection does not seem to me to be a valid one. Dr. C. A. 

 White, in a paper read before the American Association for the 

 Advancement of Science last year and published in volume 39 of the 

 Proceedings, in speaking of applying new names to fossils occurring m 

 two different formations, says that "if a given formation is found to 

 bear a fossil fauna the component members of which, with such excep- 

 tion- as have been referred to (i.e. forms considered identical in two 

 formations) are all unlike those of any other known fauna, I think it 

 admiseable to treat the whole fauna as new and to give a new name to 

 each species " (p. 242). My own studies of Scolithus led me to adopt 

 this method previous to reading Dr. White's paper, and I have there- 

 fore proposed, as seen above, to characterize the species of Scolwt** 

 upon the formation, and not, as has been done at times, the formation 

 on the occurrence of the species." 



The paper by Mr. James was discussed by N. S. Shaler and E. W. 

 Claypole. Professor Shaler advised neglecting altogether the specific 

 names for Scolithm, since it is at best only a hole in the rock. He 

 also regarded Billings' observations on sponge spicules as valueless, 

 because anything so widely distributed as these spicules would be 

 swept into small crevices or openings, such as the Scolithus perfora- 

 tions. Professor Claypole remarked that Scolithus persists to the 



The Sirocco as a Disintegrating Agent.— Mr. John B. Cooke 

 cites a number of facts (Science-Gossip Jan. 1892) to show that the 

 sirocco is an important agent in planing down and molding the hills 

 and valleys of the Maltese Islands. Its effect may be traced on every 

 rock and boulder. Of the exteriors of walls and houses, the side that 

 is exposed to the sirocco always presents an eroded and time-worn 

 appearance, while the other sides are fresh and unworn. It is not 

 uncommon to find stones almost completely worn through. In the 

 old fortifications that were erected by the Knights of St, John, such 

 phenomena are of frequent occurrence. From a series of calculations 

 of the rate of the erosion of the Globigerina Limestone in a number of 

 buildings of known ages, Mr. Cooke estimates the denudation due to 

 the sirocco at 22 tons of material annually from every acre of surface. 



