1887.] NEW YORK ACADEMY OF SCIENCES. 165 



socket is vertically excavated in the posterior lateral angle of 

 the cranium, into which a thimble-like condyle, projecting 

 from the anterior margin of the post-temporal, is fitted. In 

 Tiianichthys, the condyle of the post-temporal bone is horizontal 

 iind broad, and is clasped in a furrow at the angle of the cra- 

 nium. The post-temporals are a foot and a half wide, and, as in 

 Diniclithys, are overlapped by the clavicles below and by the 

 dorso-median plate above. This plate is subcircular in outline, 

 and has a long, slender, furrowed process, projecting back- 

 ward and downward. Like all the other bones of Titanich- 

 tliys, it is much thinner than in Diniclithys. The suborbital bones 

 ^re ovoid, pointed anteriorly, with a broad but shallow excava- 

 tion above; they are eighteen inches in length. The mandibles 

 are three feet long, the posterior end spatulate, six inclies wide, 

 ,and turned downward instead of upward, as in Dinichtliys. The 

 -anterior end is turned up like a sled runner, and is excavated in 

 a deep furrow somewhat as in Tiianiclithys Ayassizii, but the 

 whole jaw is much heavier and broader. The under side of the 

 body was protected by a triangular plate three feet long and 

 nearly as broad, having a deep sinus posteriorly and a rounded 

 projecting angle near the middle of either side. In honor of 

 the discoverer, this great fish has been named Titaniclithys 

 Clarkii. 



Prof. Henry Drummond, F.R.S.E., F.G.S., of Glasgow, 

 delivered a lecture, entitled: 



THE HEART OF AFRICA. 



Mr. George F. Kunz exhibited and described polished sec- 

 tions of 



JASPEEIZED and AGATIZED woods from ARIZONA. 



At the meeting of the Academy on October 5th, 1885, the 

 writer described jasperized and agatized woods of Arizona, and 

 called attention to the magnificent colors and the remarkably 

 large sections of trees, which, to all appearances, would furnish 

 art objects such as had never been seen before, and it was sug- 

 gested that possibly perfect sections could be produced from two 

 •to three feet in diameter. Until very recently, however, it 



