ACADEMY OF SCIENCES. 159 
ECHINOMETRADZ. 
Colobocentrotus atratus, Brandt. 
Specimens collected at the Paumotu Islands. Collected and presented by 
Capt. M. Turner. ‘The species occurs also at Zanzibar, Java, and Sandwich 
Islands. 
‘*Stimpson says that CU. atratus is found at the Bouin Islands, adhering, 
simply by their suckers, to the perpendicular faces of rocks, exposed to the 
full fury of a Pacific Ocean swell. We must remember that the test of this 
genus forms, with its spines, a flat segment of a sphere, and that the close 
pavement of polygonal spines presents but little surface to the action of the 
water. The suckers of the actinal side are also very powerful and numerous,”’ 
—A. Agassiz, ‘‘ Rev. Echini.”’ 
SCUTELLIDA. 
Mellita testudinata, Klein. 
Specimens from Galveston, Texas, presented by Mr. J. R. Scupham. 
Dr. Blake called the attention of the Academy to investigations 
he is making in determining the molecular properties of minerals. 
Reeutar Merrtine, Aucusr 16, 1875. 
President and Vice-Presidents being absent, Dr. Kellogg was 
called to the Chair. 
Twenty-five members present. 
Donations to the Museum: Silver ore from Nevada, from O. 
G. Leach. Thirteen specimens of ore, from Louis Lewis. Three 
specimens of ore, from L. Kaplan; Twenty specimens of Duran- 
gite, from Jos. T. Boyd. Five specimens of ore, from B. B. Minor. 
Four specimens of ore, from Geo. W. Dent; also from the same 
donor, nut gall, vegetable wax from the Andes, Orchilla from 
Mexico, Camel’s hair from Calcutta, and Chinese envelopes. 
From A. J. Severance, specimens of rock, (core from Diamond 
Drill) from Oregon, California and Australia. Quicksilver ore 
from Santa Clara County, from A. K. Grimm. Silicified wood 
found 300 feet deep in Manzanita Mine, Nevada County, Cali- 
