August 21, 1885.] 



SCIENCE. 



143 



August are so much longer than the other months. 

 This impression of the months applies only to the 

 current year. 



When thinking of any event that occurred more 

 than one year ago, 1 have an entirely different scheme 

 presented. The second figure illustrates it. The 

 centuries are arranged in columns, decreasing in 

 length until the Chi'istian era, beyond which the 

 lapse of time is denoted by an inclined line here 

 shown. 



Important dates I think of as lines crossing these 

 columns; and the life of a noted man, or a war, as 

 the space included between two such lines. 



149-2 



1776 



1812 



100 1400 1500 1600 1700 1800 



I should have said, that in these columns the 

 decades are marked by especially distinct lines. It 

 seems to me there is in these mental associations a 

 large and interesting field for study ; and I, for one, 

 would be glad to hear other facts bearing on the sub- 

 ject. C. RUHEIT. 



New Haven, Aug. 6. 



The classification and paleontology of the 

 U. S. tertiary deposits. 



In the issue of this journal of June 12, Prof. A. 

 Heilprin condemned the second part of my article on 

 the genealogy of the tertiary mollusca of the United 

 States before it had been published. Since its appear- 

 ance, moreover, he has again recurred to the subject 

 in a note in Science of July 31. I would here beg 

 permission to defend myself from the charges that 

 he brings forward. 



I have shown that the literature affords no evi- 

 dence, either paleontological or stratigraphical, that 

 the Yicksburgian is the most recent formation ; and 

 have given a number of reasons, based upon profiles 

 which I have observed, showing that this bed is most 

 probably the oldest. Professor Heilprin, however, 

 has nothing whatever to say on these subjects. What, 

 then, does he say ? 



1. ''It might appear . . . that the paleontologi- 

 cal evidence was in conflict with that derived from 

 stratigraphy. As a matter of fact, however, the 

 paleontological evidence ... is, as we now know it, 

 absolutely confirmatory of the pregnant facts which 

 the stratigraphy of the region presents; and, indeed, 

 it would be difficult to find a region of similar deposits 

 where it is more so." When he wrote this. Professor 

 Heilprin must have entirely forgotten what he him- 

 self had published on the fossils from Wood's Bluffs, 

 (Proc. ac. nat. sc. Phil., 1880, 364-375). There he 

 points out, in spite of certain wrong determinations, 

 clearly and in extenso, the conflict between paleon- 

 tological and stratigraphical evidence (see pp. 368, 

 369). 



2. " The absence or scarcity of forms of a dis- 

 tinctively old-type facies in the Vicksburg beds, and 

 the introduction there of new forms whose equiva- 

 lents or immediate representatives are known only 

 from the newer horizon, are sufficient in themselves 



to establish the position." This statement of Profes- 

 sor Heilprin is new and wholly without proof. My 

 studies lead me to precisely the opposite view. In the 

 Yicksburgian are contained the old forms, while in 

 the Claibornian the new ones make their appearance. 

 The facts upon which I base this statement will be 

 given in another place. 



3. I have contested the right to consider and map 

 all localities with Orbitoides as oligocene. Professor 

 Heilprin objects to the older authorities, hence I will 

 here quote the following very recent one. Zittel's 

 Handbuch, vol. i., Munich, 1876-80, p. 103, says, 

 " Orbitoides ... In der obersten kreide, sehr ver- 

 breitet im eociin, im miocan selten." If Professor 

 Heilprin can cite any authority, stating that Orbi- 

 toides occur only in the oligocene, I shall be very 

 glad to have him do so. 



4. Then Professor Heilprin speaks of Zeuglodon. 

 He argues, Zeuglodon is ' leitfossil ' for the Jackso- 

 nian; it is known in Europe in late eocene ormiocene 

 deposits, hence the inference is that the Jacksoniau 

 must be late eocene (or miocene?); the Claibornian 

 is middle eocene (Parisian), consequently the Jackso- 

 niau overlies the Claibornian. To give to this argu- 

 mentation some weight, it will be necessary for Pro- 

 fessor Heilprin to prove : First, That Zeuglodon occurs 

 only in the Jacksoniau, and not elsewhere in America. 

 Having studied the known facts which have been 

 published, and having myself seen and collected Zeu- 

 glodon at different localities in the South, I have as 

 yet not found evidence to convince me of the truth 

 of this statement. Second, That he has a right to 

 parallelize the Jacksoniau with any European bed 

 from the presence of a single genus. I found a small 

 bivalve in Jackson, which I should compare with 

 specimens of the genus Kelliella, Sars. If, however, 

 a genus (not a species) can be determined from 

 figures and descriptions alone, there can be no doubt 

 that this fossil belongs to this genus, hitherto only 

 known as recent (and pliocene?) in Europe. Has 

 any one a right to draw from this the conclusion that 

 the Jacksoniau bed is recent or pliocene ? Third, 

 That the Claibornian is middle eocene. My studies 

 and comparisons have demonstrated to me that it 

 would be a laborious and difficult task to paral- 

 lelize the sub-divisions of the American old-tertiary 

 with those of the European. So far as I am aware, 

 my material for this purpose exceeds that of any 

 other collection. Hitherto I have ascertained noth- 

 ing to prove that the Claibornian is middle eocene, 

 although it may yet be proved. If Professor Heilprin 

 can prove two of these three-mentioned points, with- 

 out the third one, there will be nothing convincing 

 in his argument 'to the mind of any unprejudiced 

 paleontologist.' 



5. "In that which relates to the oligocene (Orbi- 

 toide, Nummulite) rock of Florida, whose existence 

 appears to give Dr. Meyer a considerable amount of 

 anxiety, and which would better suit the requirements 

 of the new theory were it cretaceous, our author need 

 entertain no doubts. The rock is there," etc. I 

 have not the least doubt about the existence of orbi- 

 toidic limestone in Florida, observed by E. A. Smith, 

 nor have I anywhere expressed such. This limestone 

 causes me no anxiety whatever. I fail to see why 

 this limestone, if Vicksburg is the oldest bed, should 

 be cretaceous. I have nowhere expressed this belief, 

 nor do I think it will prove to be of this formation. 

 All that I have said is, that there is no reason to map 

 as oligocene localities where orbitoidic limestone is 

 observed, or the larger areas, where nothing at all 

 has been observed. 



6. " In such inquiry, it is necessary, however, to 



