Geology and Natural History. 399 



granite, which probably represent phases of a parent magma. 

 The various changes induced in these rocks through mechanical 

 deformation in two of the areas and through chemical alteration 

 alone in the third have been carefully studied and many features 

 of interest are developed. l. v. p. 



7. West Virginia Geological /Survey, vol. 1 ; by I. C. White, 

 State Geol. (Morgantown, West Va., 1899, 8°, 392 pp.) — In addi- 

 tion to the administrative report this volume contains a discussion 

 of magnetic declination for the state with description of meridian 

 monuments by R. U. Goode. The State Geologist himself con- 

 tributes a list of levels above tide and a particularly valuable 

 report on the petroleum and natural gas of the state. This is 

 treated both from theoretic and practical standpoints and will be 

 found of great service to those engaged in a study of these 

 products. It is to be hoped that the state will continue the sur- 

 vey and permit the publication of other valuable material which 

 has been accumulated. l. v. p. 



8. A neio and interesting olivine-melilite-leucite rock. — The 

 rock of one of two small volcanic cones discovered by E. Clerici 

 at San Yenanzo in Umbria, about half way between Orvieto and 

 Perugia, has been described by V. Sabatini in a note (dated 

 September, 1898) in the Bolletino del Reale Comitato Geologico 

 for 1898, as a leucitic melilitite with olivine. Olivine occurs as 

 phenocrysts, and the groundmass is composed of melilite, leucite, 

 black mica, and a little pyroxene, nephelite and magnetite, feld- 

 spars being absent. The melilites are zonally built, the interior 

 being optically positive and the exterior negative. Sabatini pro- 

 poses for this type the name Venanzite. 



At the meeting of the Berlin Academy of Sciences held Feb. 9, 

 1899 (Sitzungsberichte, vii, p. 110, 1899), Prof. Rosenbusch 

 read a paper on " Euktolite, a new member of the theralitic effu- 

 sive magmas." This rock is identical with that of Sabatini, com- 

 ing from the same locality, and his description is practically the 

 same though more detailed, and with chromite and perofskite 

 added to the list of component minerals. An analysis gave : 



Si0 2 41-43, Ti0 2 0-29, A1 2 2 9'80, Fe 2 3 3*28, FeO 5*15, MgO 

 13-40, CaO 16-62, Na a O 1-64, K 2 7'40, H 2 I'll = 100-12. 

 P 2 5 none. Sp. gr. = 2-758. 



He compares it with the madupite of Cross, leucitites, and 

 leucite and melilite basalts, all of which belong to his theralitic 

 magmas. The name is derived from evktos, desired, since it 

 is " a desired example for the validity of my representation of 

 the intimate connection of the eruptive rocks throughout the 

 world." Sabatini's name Venanzite antedates Euktolite by about 

 five months and on the grounds of priority is unquestionably the 

 one by which this interesting type should be known, especially 

 since it is formed from the type locality, in accordance with 

 modern usage in petrography, and does not involve the tacit 

 acceptance of any theory, however generally recognized. 



h. s. w. 



