2 MEMOIRS NATIONAL ACADEMY OF SCIENCES. [vol. xiv. 



one of the papers cited by Agafonov.^ In this the stone is described as composed chiefly of 

 chondrulcs, entire and fragmental, embedded m a groimd of crystals and crystal fragments. 

 The mineral composition is given as olivine, bronzite, augite, maskelynite, nickel-iron, and 

 troilitc. Brozina describes it^ as having suffered from oxidation to a depth of 1-3 cm. below 

 the original siuiaco, as of a brecciated structure and with strongly developed sUcken-sided 

 surfaces (Ilarnischflachen) . He classes it a brecciated chondrite (Cib) , though with occasional 

 black chondniles showing a gradation into the brecciated spheruhtic chondrites (Ccb). One 

 fragment badly oxidized he seems mclined to class as a crystalline chondrite (Ck). Meunier 

 in his hst' states that wliile the characteristics are not absolutely identical with those of Tad- 

 jera, the composition is the same and the differences not sufficiently marked to justify relegat- 

 ing to a distinct type. Neither says anything of the mineral composition other than is to be 

 inferred from the classification. 



The stone is represented m the national collection only by a small oxidized mass weighing 

 S grams and a thiix slice of the fresh, unaltered stone weighing 14 grams. A tliin section cut 

 from this last shows the stone to be of a pronounced chondritic t>^e, the entire mass being 

 composed of chondndes and fragments of chondiniles closely compressed and with a minimum 

 amount of fragmental interstitial matter. The mineral composition is nickel-iron, iron sulphide, 

 olivine, an orthorhombic and a monoclinic pyroxene, the last named polysynthetically twinned. 

 In two instances intei-stitial areas of the phosphate provisionally called "francoHte" were 

 noted and there are niunerous areas of the black irresoluble matter wliich Meunier regards as 

 fayaUte and of secondary origm. 



Judging from what has been written and my own oTsservation, the stone is of a somewhat 

 variable character. From the result of study of this one section I feel disposed to class it as a 

 veined spheruhtic chondrite (Cca). (See Fig. 2, PI. I.) 



Farmington, Washington County, Kans. — This stone belongs to the group of black chondrites 

 of Brezina, of which but eight representatives are known. The stone was seen to fall and its 

 history is beyond question. It has been described by several writers among whom only Kunz, 

 Weinschenk,* and Brezina need here be mentioned. Weinschenk, to whom the microscopic 

 descriptions are doubtless due, refei-s to the occurrence of " the mineral designated by Tschermak 

 as 'monticellite-like' formed in the usual way. This contains roimded, colorless mclusions with 

 bubbles probably of glass." Brezina= says "Auch monticeUitartige Chondren kommen vor." 

 I am miable in the five thin sections we have of this stone to find the monticeUite-like mineral in 

 chondrules. It occurs rather hi irregular cavities, sometimes completely filling them and some- 

 times merely small, colorless crystalhne plates Knmg their waUs. (See Fig. 1, PI. II.) Naturally 

 there was at once suggested the possibihty that these were a phosphate, a possibihty made a 

 certainty by treating one of the areas in an uncovered slide with a drop of acid ammonium 

 molybdate, when the mineral was quite dissolved, giving rise to abimdant crystals of the phospho- 

 molybdate of ammonium. I have been xmable to detect the "asymmetric feldspar," the 

 presence of which was thought to be indicated by the chemical analysis. The stnicture is, how- 

 ever, very obscure, and it is yet possible that a mineral of this nature may exist and be xmrecog- 

 nizable. Meimier's conclusions relative to the secondary nature of the dark color m the black 

 chondrites are well supported by a comparison of slides of this stone with those from a roasted 

 fragment of Homestead. 



Forest City, Winnebago County, Iowa. — The only mineralogical description of this stone 

 that has thus far been given is that of Kunz.' This is incomplete and imsatisfactory, made 

 evidently without recourse to thin sections and a microscope. He describes it as a "typical 

 chondrite, apparently of the type of the ParnaUite group of Meimier . . . A broken surface 

 shows the mterior color to be gray, spotted with brown, black, and white, containing small 



> Rev. des Sciences Naturelle, St. Petersburg, no. 1, 1891, p. 41. 



! Die Mcteoriten Simmlung, 1895, p. 249 . 



' Revision des Pierres Motoorique, 1894, p. 413. 



< Min. u. Pet. Mittheil. vol. 12, 1891, pp. 177-182, and Amer. Joum. Sci. ,voI. 43, 1892, pp. 65-67. 



' Weiner Sammlung, 1895, p. 253. 



« Amer. Joura. Sci., voL 40, 1890, pp. 318-320. 



