348 liECORD OF SCIENCE FOR 1887 AND 1888. 



Hatch, Fredkiuck IT. On a Ilornblemle Hypersthone Peritlotite from liOsilwa, a 

 low bill iu Tavcta District, at the S. footof Kilimaujaro, East Africa. Geol. Mag., 



June, 1888, p. 257. 



Hawortii, Erasmus. A contribution to the Arcb;ean GeoU)gy of Missouri. Am. 

 Geol. Mag., 1888, p. 280. 



Describes the eruptive rocks in the vi(;inity of Pilot Knob and Iron Mountain, 

 Missouri. These consist of (1) grauite, (2) porphyries and porphyrites, {^.^) dia- 

 bases and diabase porpbyrites. The quartzes of the granites show often a de- 

 cided approach to aa idiomorphic structure and the orthoclases, iu places, sec- 

 ondary enlargements. Topaz wJis fonud iu slides from near the mineral veins. 

 A large share of the rocks is described as quartz porphyries and porphyrites, in 

 some of which occurs the rare uiiinganese epidote piedmontite. 



A contribution to the Archieau Geology of Missouri. Johns Hopkins Univ. 



Gil-., April, 18W, p. 70. 



Hknueksox, G. G. Note on the composition of a Carbonaceous Sandstone. Trans. 

 Geol. Soc. of Glasgow, 188li-'87 -'88, vol. viii, part li, p. 27(). 



Hkkriciv, C. L., W. G. Tight, and H. L. Jones. Geology and Litbology of Michi- 

 picolen Bay. Results of the Summer Laboratory session of 18'S(). iiull. Soc. 

 Laboratories, Deuison Univ., 1887, parts 1 and 2, vol. ii,p. Hi). 



E. S. Clarke, and J. L. Deming. Some American Norytes and Gabbros. 



Am. Geol., June, 1888, p. S.'JO. 



Hettner, a., and G. Lincic. Beitriigezur Geologie nud Fetrographie der Columbia- 

 nischen Anden. Zeitschnft deuts. geol. Gesell., XL, Band, 2, Heft, p. 20."). 



HlBSCH, J. E. Ueber einige miu<ler bekannte Eruptivgesteine des bohmischen Mittel- 

 gebirges. Min. u. pet. Mittheilungen, 9. B., il, u. iil, pp. 2:52-202. Six figures in 

 text. 



Hill, E. The Rocks of Sark, Herm, and Jethou. Quar. Jour. Geol. Soc, No. 171, 

 August, 1888, vol. XLiii, p. 322. 



The principal features are a mass of Archieau gneissoid rocks consisting of 

 quartz, feldspars, dark green or black hornblende and microscopic apatites and 

 spheues. This is overlaid by a hornblendic schist consisting of alternating bands 

 of very pure hornblende and feldspathic material with occasional quartzes. This 

 rock often shows false bedding and is regarded as a possibly metamorphosed vol- 

 canic ash. This in its turn is overlaid by a mass of granitic or syenitic igneous 

 rock. The whole subsequently cut by a series of dikes including quartz-feisite, 

 <liabase3, and kersantites. 



Hinue, George Jennings. On the chert and siliceous schists of the Permo-Carbon- 

 iferous stnita of Spitzbergen, and on the characters of the sponges therefrom, 

 which have been described by Dr. E. von Dnnikowski. Geol. Mag., June, 1888, 

 p. 241. 



Ou the organic origin of the chert in the Carboniferous limestone series of 



Ireland, and its similarity to that in the corresponding strata in North Wales aud 

 Yorkshire. Geo], Mag., October, 1887, p. 435. 



The paper is largely controversial. The author shows apparently conclusively 

 that the cherts in question are formed mainly from the siliceous residues of 

 sponges. 



lIoBBS, William H. On the rocks occurriug in the neighborhood of Ilchester, How. 

 ard County, Maryland. Being a detailed study of the area comprised iu sheet 

 No. 16 of the Johns Hopkins Univ. Circular, April, 1888, p. 69. (A preliminary 

 notice; the full paper, with map aud plates, in course of preparation.) 



Describes the rocks as hypersthene gabbro locally altered into gabbro diorite, 

 olivine hyperite, diorites, pyroxeuite, and granite containing abundant accessory 

 allanite. 



Holland, P., aud E. Dickson. Examination of (inartzites from Mills Hill, Pontes- 

 bury. Proc. Liverpool Geol. Soc, 1887-'88, vol. V, part IV, pp. 380-384. 



