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SCIENCE 



[N. S. Vol. XXXVIII. No. 986 



and New York are known by other names, 

 and the discussion of their correlation raises 

 delicate questions of fact and interpretation. 



A very distinctive part of the paleontolog- 

 ical chapters is Professor Schuchert's treatise 

 on the cystids, a somewhat expanded account 

 of his earlier descriptions and illustrations 

 of these genera and species which attained a 

 noteworthy development in the " Keyser mem- 

 ber." There are attractive novelties among 

 the crinoids, fine Bassler-photos appear among 

 the Bryozoa, familiar drawings among the 

 profusion of brachiopods and MoUusca, very 

 interesting trilobites, regarding which the 

 writer ventures to intimate (by way of neutral- 

 izing too much blandiloquence) that Homa- 

 lonotus swartzi Ohern (PL 90) is H. vanux- 

 emi Hall (vanuxemi-major-perceensis type), 

 that Dalmanites Tceyserensis Swartz (PI. 91, 

 Figs. 5, 8, 9) is D. micrurus Green and that 

 the object figured on PI. 92 (Fig. 3) as the 

 hypostoma of D. multiannulatus Ohern is not 

 an hypostoma, but the very interesting bifur- 

 cate anterior limb of the cephalon. 



Volume 2 opens with a discussion of the 

 Middle Devonian, its subdivision and corre- 

 lation, the major part of which is by Dr. 

 Prosser, who has, with his usual perspicacity 

 and justness, discussed the characters of these 

 sediments and their correlation values. The 

 Maryland geologists have felt impelled to fol- 

 low the usage of the IJ. S. Geological Survey 

 in adopting the term " Romney " (West Vir- 

 ginia place-name) to embrace the members 

 which in New York are known as the Onon- 

 daga, MarceUus and Hamilton. Each of these 

 is a recognizable factor in the composition of 

 the Eomney although the Onondaga has a 

 distinctly peculiar development in lithology. 

 And, says Dr. Prosser, " there are obstacles in 

 the way .of attempting to map these divisions 

 separately due largely to the gradual change 

 from the lithologieal characters of one mem- 

 ber to another. ... It was thought best to 

 regard the stages as constituting one forma- 

 tion." The distinctive character of the 

 Onondaga member is a matter of much in- 

 terest because of its essential departure from 

 its calcareous expression at the north. Lime- 



stone deposition is largely replaced by black 

 shales of the type of the Marcellus, and would, 

 in the opinion of Dr. Swartz, who has con- 

 tributed the special section on this forma- 

 tion, indicate the increase southward of the 

 replacement which is already evident in west- 

 ern New York. 



Dr. Kindle contributes a concluding and 

 philosophical chapter on the relations of the 

 faunas to the sediments. 



The systematic paleontology of the Middle 

 Devonian has been prepared chiefly by Drs. 

 Prosser and Kindle, the Bryozoa by Drs. Ul- 

 rich and Bassler. 



Thereupon follows a treatise on the Upper 

 Devonian deposits by Drs. Prosser and 

 Swartz, with the correlation essay and the 

 local sections by Swartz, and finally the de- 

 scriptive paleontology by Clarke and Swartz. 

 The entire Upper Devonian series in Mary- 

 land is divided into a lower marine — the Jen- 

 nings formation — and an upper non-marine — 

 the Catskill. In the matter of stratigraphy 

 and faunal succession the Maryland Upper 

 Devonian shows a closer relationship with the 

 carefully elaborated Upper Devonian of New 

 York than is as yet known from any other 

 region outside the latter. But even with this 

 close affiliation it has seemed necessary to 

 meet present requirements by interposing 

 new stratigraphic terms. The black shale 

 and peculiar fauna of the Genesee member at 

 the base of this series stand confirmed, but 

 above it the Portage beds with the Naples 

 fauna and the higher Ithaca fauna are em- 

 braced by the term " Woodmont shale mem- 

 ber." Overlying is the "Parkhead sandstone 

 member " which seems, in place and fauna, 

 to be equivalent to the Enfield member or 

 Unadilla terrane of New York {Ithaca in its 

 old and broader sense). The "Chemung 

 sandstone member " has effectively the place 

 and value of the Chemung in New York. 



What has been thus said may serve to indi- 

 cate in small part the purport and present- 

 ments of this work. Its collaborators have 

 done honorably and with credit to them- 

 selves and their themes in perfecting an en- 

 cyclopedia of a great geological system in an 



