Correspondence. 333 
vctii. Under the circumstances, therefore, the assumption tiiat by the 
arrangement of the two new forms which he took that occasion to de- 
scribe McCoy intended to designate A. plaiiiradiatus (now, according 
to Hind, A. tabiilatus) as the type of Avicnlipcclcn, seems unjustified, 
especially since it is quite certain that A. docens (now, according to 
Hind, .1 scviicostalus) was the species which McCoy figured to show 
the structures of Avicidipecten, and which, according to his own state- 
ment, was the one that taught him the distinctive characters of the genus. 
It seems to me clear, therefore, tliat ./. docens McCoy {'=.1. Hexuosiis 
'McCoy=ii.l. Si'iiiicostatiis Portlock) is the only species whicli with pro- 
priety can be considered typical of /ivicidipccten. 
GEORGE H. GIRTY. 
PERSONAL AND SCIENTIFIC NEWS. 
IDr. Edward M. Kraus has been appointed instructor in 
mineralogy at the University of Michigan. 
Amon'g the topographical maps recently issued by the 
United States Geological Survey are the following: Park- 
ersburg. W. A'a. ; Vanceboro. N. C. ; San Diego, Calif.; Apal- 
achin, N. Y. : Boston, Mass. ; Bastrop, Texas ; Honeoye, N. Jl". 
James Walter Goldthwait, of Lynn, Mass.. has been 
ajipointed instructor in geology in Northwestern University. 
Mr. Goldthwait took his college course at Han/ard, where he 
has' also done graduate work and where he has been for two 
years past teaching fellow. 
The. fourth New England intercollegiate geological 
EI ELD excursion was held at Worcester, Mass., on Saturday, 
Oct. 22, under the direction of Mr. Joseph H. Perry of the 
Worces'ter High School. The excursion was attended by over 
forty persons, including representatives of Amherst, Plarvard, 
Massachusetts Institute of Technology-, Smith, Wellesley, Wil- 
liams, \\"orcestcr Polytechnic, and Yale, and of St. Mark's 
School, Worcester Academy, Worcester High School and 
^Vorcester Normal School. A general statement of the prob- 
lems to be studied was made by Mr. Perry on the evening be- 
fore the excursion in the rooms of the Worcester Natural His- 
tory Society. The field localities showed outcrops and quarries 
of slates and quartzytes. assigned to the Carboniferous period, 
greatly deformed and eroded, with many large arKl small gran- 
itic intrtisions. An excursion to some point on the sea coast 
will prohably be made next year. 
