MENS a Gh Cay Ca eae Seat RE Me ee gee ay y= RE Oa fe ene. Say ee ee LP Three ES Crys nee ee eae TES 
E. B. Andrews on Petroleum in its Geological Relations. 33 
pty Radiates in this respect, but gies feet and Polyzoa fixed 
n the lowest class of Radiates, the Poly 
We would tis have 
ALPHATYPIC, eae Po Fishes, 
GAMMATYPIC, Gasteropods, Ar doveay Worms. 
BeratyPio, La ellbranchiates, Saccat 
Tun 
DrGRADATIONAL, i Brachio dé; esl 
Hemiraytow, Poly Radiates, Polyps. 
XPLANATION OF PHE 
RK zoa; B, Brachio niet ls i nips ein ah he G, Gasneuean 
and C. phalopod —-_(M, aad cating Monomyaria of the second s ese 
figures are represented anterior end downward, the dorsal region being turned to 
the left. The tube within each cut, represents the intestine, the larger end of 
which is the mouth, and the smaller end the anus. The ia ates figure repre- 
sents the heart, and the star represents the pedal ganglion 
ERIES Represents similar views, with less detail. “The dorsal region in ee 
series is uppermost, and the posterior boy is turned to the left, as indicated by arro 
A. The curved line indicates the intestine, the large end being the mouth. 
ran Tl [. Represents transverse sections of sericea lama n Series IT. 
epresents the mean position in nature, of the Saitaan poulaasse axes 
of thik fives represented a : A, Anterior pole ; P, Posterior pole. e verti- 
cal rows of figures are sdeaticad. 
Art. IV.—Petroleum in tts Geological Relations; by Prof. E. B. 
ANDREWS, Marietta, Ohio 
N the number of this Journal for July, 1861, I gave some 
facts bearing ea the geological relations of petroleum. My 
attention at that time was confined chiefly to those locations 
found in the Coal-measures of West Virginia a Southern Ohio. 
It is gratifying to know that the views presented in that paper 
have since been fully verified. As predicted, by far the larger 
part of the oil produced has been found along the axis of a well- 
marked anticlinal, extending from the borders of southern Ohio, 
forty miles or more, into West Virginia, through Wood, Ritchie 
and Wirt counties. A smaller quantity has been found in the 
tolinca rocks of Ohio; while scarcely a barrel has been ob- 
tained in horizontal rocks, although hundreds of thousands of 
generation of oil have existed over a wide area; but the physical 
condition of fissures is found to exist in comparatively iat 
reas. Fissures serve two purposes, one to give space for the 
formation and expansion of the hydro-carbon vapors, and th 
other to furnish receptacles for the oil when condensed. 
ures must connect with the deeply seated sources of ot oil 
Am. Jour. Sct.—Szconp Serizs, Vou. XLII, No. 124.—Juxy. 
5 
