999 [ FEBRUARY) 
thorax, with traces of oblique striw, near the base; marginal stria distinct, but 
not extending in front of the middle; epipleurz sparsely punctured, with indis- 
tinct traces of a lateral line. Pygidium strongly inflexed, finely punctured. 
Body beneath coarsely punctured; anterior tibiw somewhat suddenly and broadly 
dilated. ; 
2. B. misellus, rotundatus, convexus, rufus, nitidus, thorace parce punc- 
tulato, elytris punctatis, stria marginali integra, pygidio levi. Long. :03. 
Two specimens from New York, under bark. Similar in form to the pre- 
ceding, but much smaller; the thorax is more finely punctured; the marginal 
stria of the elytrajis entire, anteriorly receding from the margin; the lateral 
stria appears more distinct than in B. tantillus; the pygidium is smooth; under 
surface and feet as in the preceding. 
§2. Pygidium perpendiculare; elytra acute marginata. 
3. B? marginatus, rotundatus, modice convexus, niger, subnitidus, dense 
grosse punctatus, elytris margine Jaterali acuto, pygidio punctulato. Long. -06. 
One specimen from [llinois; Mr. Willcox. Body rounded, slightly and regu- 
larly convex, forming a small segment of a sphere, black, somewhat shining. 
Head densely punctulate. Thorax densely punctured, lateral margin longitudi- 
nally impressed. Elytra coarsely punctured, with slight vestiges of external 
oblique striz at the base; exterior margin sharply defined; marginal stria obso- 
lete; epipleure broad, flat, bistriate. Pygidium perpendicular, finely punctured. 
Under surface punctured, feet rufous, anterior tibie curved inwards, slightly 
dilated; posterior tibiae very slender. 
The Committee on the following paper by Dr. Greene, reported in 
favor of publication in the Proceedings. 
Chemical Investigation of Remains of Fossil Mammalia. 
By Francis V. Greenr, M. D. 
At the request of Dr. F. A. Genth, I have made in his laboratory a chemical 
investigation of several fossil retains, collected by D. D. Owen, M. D., ini his 
late survey of Nebraska Territory. The specimens, which consisted of a brown 
portion of bone froma Titanotherium, the enamel and dentine of a tooth of the 
same animal, and a portion of the tibia of an Archeotherium, were kindly fur- 
nished me by Dr. Joseph Leidy from the collection of the Academy of Natural 
Sciences... ' 
The general outline of the methods pursued in determining the constituents of 
these specimens is as follows : 
The finely-powdered substance, being always dried over sulphuric acid, was 
dissolved (according to H. Rose’s method for the determination of phosphoric 
acid) in nitric acid, and after adding mercury in sufficient quantity to combine 
with the phosphoric acid, it was evaporated to dryness ina water bath. Afterwards 
it was moistened with water and again evaporated to dryness; this operation being 
repeated until no odor of nitric acid could be observed at the temperature of the 
water bath. To this dried mass water was now added. The insoluble portion 
consisted only of phosphate and basic nitrate of mercury, (except in one analysis, 
in which iron existed in determinable quantity ;) the solution contained fluoride 
of mercury and the other constituents as nitrates. This was filtered off, and 
the insoluble phosphate, after being washed and thoroughly dried, was fused 
with carbonate of soda, with all the precautions mentioned by Rose. The fused 
mass, consisting only of phosphate of soda and the excess of carbonate of soda, 
dissolved therefore completely in water, except in one analysis, in which a por- 
tion of the iron remaining undissolved, was filtered off and determined in the 
usual manner. This watery solution was then acidulated with hydrochloric 
