—— 
Correspondence. 193 
portions of the skeleton were still unknown. Those parts which are 
best known are the skull, especially the elongated snout, and the jaws, 
the shoulder and the caudal and pectoral fins. These parts have sel- 
dom been found associated, and there have been established three ser- 
ies of species, one on the teeth, one on the snout, and the third on the 
fins. It is certain that as new collections are made and studied some 
of these sub-species will be reduced to synonymy. The author pointed 
out various errors on the part of writers in the interpretation of dif- 
_ ferent elements of the skeleton and illustrated his pointe by means 
of specimens. 
Dr. A. A. Julien gave an impromptu discussion of the relation of 
honestones to the cutting edge of tools, in the course of which he said 
that the quality of a hone depended on the size and shape of its com- 
ponent particles, and upon the cement joining the whole together, ex- 
except in the case of the novaculites from Arkansas, in which the hon- 
ing quality is due to the sharp edges of minute cavities left by the sol- 
ution of calcite; and in the case of the turkey-stone, in which the 
honing quality is due to veinlets of quartz intersecting a rock which 
has been formed by silica replacing a granular limestone. A micro- 
scopic study showed that the edge of a tool is not regularly serrated, 
part of’ it being smooth and part undulatory. Viewed on edge the 
sharpest tools are practically straight, while the others are more or 
less irregularly wavy. Viewed in the cross-section, a fine edge is seen 
to be a perfect wedge, while duller tools show a minute shoulder. 
E. O. Hovey, Secretary. 
PERSONAL AND SCIENTIFIC NEWS. 
Dr. Georce P. Merritt discussed “Rutile Mining in Vir- 
ginia”, at the meeting Feb. 12 of the Geological Society of 
Washington. 
Pror. R. S. Tarr of Cornell University is in Italy. He 
will also visit Germany and the British islands for the purpose 
of studying their drift features. 
Dr. M. E. Wapswortu, head of the Department of Mines 
and Mining in the Pennsylvania State College, has been elected 
Geologist for the Pennsylvania State Board of Agriculture. 
Dr. H. P. KUmmMet, who has been acting state geologist 
of New Jersey since the resignation of Dr. J. C. Smock last 
summer, has been appointed state geologist by the board of 
managers. Mr. Ktinmel has been connected with the New 
Jersey survey since 1892. 
Pror. G. C. BroapHEeap has an excellent review and 
epitome of the history of geological surveys in Missouri, and 
of early mining operations in the “Encyclopedia History of 
