26 



ments, all which he considered ingenious and well adapted 

 to the purpose. The R^eport was pronounced to be the re- 

 sult of an elaborate and thorough examination of the subject, 

 and to present facts of great importance, in determining the 

 economical value of American Coals. 



Mr. Blake presented for the cabinet some curious globular 

 masses of Quartz, concerning which he made the following 

 remarks: — 



On a plain situated in the valley of Quilca^ in South Peru, near 

 the city of Arequipa, and about thirty-four miles from the coast, 

 are to be found, scattered over the surface and imbedded in the 

 loose soil, a vast number of quartz balls like the one exhibited, 

 varying in size from one inch to four inches in diameter. The 

 exterior is dark reddish brown, and presents a rough surface 

 showing no marks of abrasion. When broken they are found to 

 be pure white quartz. The structure is crystalline in all of them, 

 while in some the crystals are well defined with slight interstices 

 between them, and a few have been found hollow, the central 

 cavities being lined with crystals. 



So remarkably similar, and so nearly globular are these balls 

 that many of the inhabitants of the country believe them to be 

 the work of art, and ascribe their origin to the ancient Peruvians, a 

 supposition the absurdity of which is evident on the slightest in- 

 spection. The plain over which they lie scattered is made up of 

 the debris of the neighboring mountains ; — the lofty porphyritic 

 peaks of the Andes flanked by sand-stone and gypsum. 



Dr. Gould read a paper, containing descriptions of species 

 of land shells, from the Sandwich Islands, supposed to be 

 hitherto undescribed. 



AcHATiNA ADUSTA. Testa turrita, apice pyramidata, iniperfo- 

 rata, soUda, fusco-nigricante, sursum pallescente ; anfr. 7 con- 

 vexis, levitcr striatis, ultimo subcarinato ; apertura ovali, intus 

 opalina, labro simplici, acuto, nigro ; columella eburnea, antice 

 in dentem producta. Long. 1^, lat. f poll. 



A singular shell, partaking of the characters of both Achatina 

 and AchalineUa. Occasionally, instead of being totally black, 

 there are bands of yellow. 



Stomatella concinna. Testa parvula, auriformi, tenui, striis 



