12 PROCEEDINGS OF THE ACADEMY OF 



13. The scapula acuminate in outline above the spine, with a very 



short coracoid. 



14. Broad truncate occiput with widely separated temporal fossae. 



15. The greatl}' expanded iliac bones. 



The dentition is not far removed from that of Dinothey^ium. 

 The presence of canine teeth might not prove a ground of dis- 

 tinction between Elephantidse and Eobasileus, since in both types 

 the tusk is embraced by both the premaxillarj^ and maxiilarj'- 

 bones. It thus becomes exceedingly probable that the tusk of 

 Maatodon and Elephant, regarded as an incisor by Cuvier, is 

 really a canine. But should a real peculiarity exist in this point, 

 as does in the presence of horns, the two cannot distinguish the 

 family from this order. Such range of variation is well known 

 to exist in the Artiodactyla, where some Cervidae and Antelopidee 

 are horned and some not ; and where musk-deer have canines and 

 Boridx none; or where the omnivorous section have canines and 

 lack horns, while Bomdse have horns and lack canines. 



The peculiar physiognomy of the Elephants is, as is well known, 

 produced by the enormous development of the frontal sinuses. 

 In Binotkerium this structure is greatly reduced, and in Eobasi- 

 leuH exists chiefly in the squamosal region. The physiognomy of 

 the latter is also materially affected by the great prolongation 

 forwards of the nasal bones, which support horns or processes 

 at both extremities, and hy the narrowing of the snout, produc- 

 ing a somewhat pig-like expression. The palatal surface of the 

 mouth is thus greatly elongate and narrowed, and must have 

 accommodated a very slender tongue. These modifications are 

 but subordinate, and such as we find iu difl'ereut members of the 

 same order. 



.On the Forms of Artijicial Oxide of Zinc. By George A. 

 KoENio, Ph.D. The specimen under examination is a piece of 

 brick taken from a zinc furnace of Lasalle, 111. It is a gift of 

 Mr. Ilegler, proprietor of the works, to C. E. Richtcr, M. E., 

 from whom I obtained it. I am not aware that any description 

 of its occurrence has been published, and am confirmed in this 

 belief bv the fact that it was Qiven to Mr. Kichter as a curious 

 but unknown substance. 



The surface of the brick is covered by a dirt}- greenish coating, 

 the nature of which could not be ascertained on account of its 

 extreme thinness. A part of the surface, about one inch square, 

 is covered by a cluster of long hair-like needles of a brilliant 

 white color and glassy lustre. These needles are very nearly 

 posed jtarallcl to each other and to the face of the brick, present- 

 ing somewhat the api)earance as if part of a goat's beard had 

 been cut off and put on the stone. A number of cavities in the 

 brick contain these needles also, but here they are placed trans- 

 versel}' like many minerals, for instance millerite. 



