462 Scientific Intelligence. 



species as many as would form from a quarter to a fifth of the 

 total for the Jurassic System. At that rate, its tale is nothing 

 like complete yet ; which all workers in its rocks know to be the 

 case." (90-91.) 



" The strata described are classified according to what may be 

 called the multizonal or polyhemeral system — in the main, accord- 

 ing to the scheme introduced for these strata in 1893 (Quart. 

 Jour. Geol. Soc, vol. xlix, p. 481) ; but further divisions due to 

 other investigators and to myself are dealt with. 



" The strata described are arranged among thirty-six zonal 

 (hemeral) divisions — a greater number of divisions than Oppel 

 used in 1856 for all the Jurassic rocks, of which these beds form 

 but a small part. 



"The Upper Lias part of the Junction Bed of Down Cliffs, 

 Chideock (Lower or -pre-striatidus Toarcian), is a very condensed, 

 imperfect epitome in 20 inches of about 180 feet of strata on the 

 Yorkshire coast, and of very much more when allowing for gaps. 



" Between the bifrons layer and the striatulus layer of the 

 Junction Bed there is occasionally a 2-inch layer which is all that 

 represents some 250 feet of deposit in the Cotteswolds — so that 

 about two feet of Junction Bed was formed while a thickness of 

 some 550 feet was being deposited elsewhere." (89.) 



" The President (Prof. Sol las) congratulated the author on the 

 very interesting manner in which he had presented a highly 

 technical subject. The correlation of thin seams with thick 

 deposits was a matter of great importance, and called to mind 

 Suess's remarks on the partings in the Trias. It might afford 

 some hints as to the order of magnitude of the scale of time. If 

 we assumed that one foot of sediment might accumulate in a 

 century, in an area of maximum deposition, then in the case of the 

 seam two inches thick which was represented by 250 feet in the 

 Cotteswolds, the rate of formation would be less probably than 

 one foot in 150,000 years. 



" The Author, in reply, remarked that Jurassic zones were 

 by no means the result of local observation only ; they had been 

 followed widely, even the new ones ; the thinness of zones was 

 no test of their importance or otherwise, being often only a local 

 accident of alternating deposition and denudation. The net 

 increase of deposit must have been much less than one foot in 

 a century, as this seemed too rapid for the faunal changes in- 

 volved." (109, 110.) c. s. 



5. Palmontologia Universalis, ser. II, fasc. IV, 1910. — This 

 fasciculus contains 11 sheets redescribing 35 species of fossil 

 echinoderma and mollusca, and completes the second series hav- 

 ing 169 sheets. The entire set may be had for $8.00 of G. E. 

 Stechert, 9 East 16th St., New York City. c. s. 



6. Geologic Atlas of the United /States. Folio 169, Watkins 

 Glen- Catatonia,, New York, 1909 ; by H. S. Williams, R. S. 

 Tare, and E. M. Kindle. — The topography and the Quaternary 

 deposits are described in detail by Tarr, the Upper Devonian 



