292 , ' [February, 



thorax, with traces of obliqua strioe, near the base ; marginal stria distinct, but 

 not extending in front of the middle ; epipleurae sparsely punctured, with indis- 

 tinct traces of a lateral line. Pygidium strongly indexed, finely punctured. 

 Body beneath coarsely punctured; anterior tibiae somewhat suddenly and broadly 

 dilated. 



2. B. misellus, rotundatus, convexus, rufus, nitidus, thorace parce punc- 

 tulato, elytris punctatis, stria marginali Integra, pygidio laevi. Long. -OS. 



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 elytra is 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 margme laterali acuto. pygidio punctulato. Long. -06. 



One specimen from Illinois; 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 striae at the base ; exterior margin sharply defined; marginal stria obso- 

 lete ; epipleurae broad, flat, bistriate. Pygidium perpendicular, finely punctured. 

 Under surface punctured, feet rufous, anterior tibiae curved inwards, slightly 

 dilated; posterior tibice very slender. 



The Committee on the following paper by Dr. Greene, reported in 

 favor of publication in the Proceedings. 



Chemical Investigation of Kemains of Fossil "Mammalia. 

 By Francis V. Greene, M. D. 



At the request of Dr. F. A. Genth, I have made in his laboratory a chemical 

 investigation of several fossil remains, collected by D. D. Owen, M. D., in his 

 late survey of Nebraska Territory. The specimens, which consisted of a brown 

 portion of bone from a Titanotherium, the enamel and dentine of a tooth of the 

 same animal, and a portion of the tibia of an Archceotherium, 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 in a 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 thcToughly 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 



