554 REPORT OF NATIONAL MUSEUM, 1890. 



cross section bears a crude resemblance to Hebrew writing (see speci- 

 mens 10771, 3857, 69548, 4081, 35121, 39100, and 37927, and Fig. 4, PI. 

 cxxv. Aplit is a name used by the Germans for a granite very poor in 

 mica and consisting essentially of quartz and feldspar only (specimen 

 No. 36151 from Scbemnitz, Hungary). The names granitell and binary 

 granite have also been used to designate rocks of tbis class (specimen 

 25115 from Missouri). Greisen is a name applied to a quartz mica rock 

 with accessory topaz occurring associated with the tin ores of Saxony 

 and regarded as a granite metamorphosed by exhalations of fluoric acid 

 (specimens 3364, 36165, and 36166). Luxullianite and Trowlesivorthite 

 are local names given to tourmaline or tourmaline-fiuorite granitic 

 rocks occurring at Luxullian and Trowlesworth, in Cornwall, England 

 (specimens 36113 and 39002). The name UnaMte has been given to an 

 epidotic granite with pink feldspars and occurring in the Unaka Moun- 

 tains in western North Carolina and eastern Tennessee (specimen 

 36784). 



The name granite porphyry is made to include a class of rocks placed 

 by Professor Rosenbusch under the head of u gangesteine," or dike 

 rocks, and differing from the true granites mainly in structural features. 

 They consist in their typical forms of orthoclase feldspars and quartzes 

 i)orphyritically developed in a finer noncrystalline aggregate of the 

 minerals common to the granite group. The characteristic features of 

 the rocks so far as revealed by baud specimens may be best understood 

 by referring to the collections (specimens 3873, 36219, 36220, and 36221, 

 from Saxony, Germany, Silesia, and England). 



The following localities and varieties are represented: 



Muscovite granite : Hansdorf, Silesia, 36152 ; Schruenitz, Hungary, 36151; Raymond, 

 Maine (with garnets), 12251; Barrington, New Hampshire, 29515. 



Pegmatite: Auhurn, Maine (polished slah), 39100; Minot, Maine (with tourmalines), 

 35966; Stowe, Maine, 10771; Portland, Connecticut, 35121; New Bedford, Mas- 

 sachusetts, 4081 ; Jefferson, Clear Creek County, Colorado, 69548; Limhach, near 

 Penig, Saxony, 3857. 



Muscovite hiotiie granite: Musquito Gulch, Park County, Colorado, 68813; G< orge- 

 town, Clear Creek County, Colorado, 36163 ; Musquito Gulch, Park County, Colo- 

 rado, 36882; Canton Haag, in the Vosges Mountains, Germany, 36164; Vosges 

 Mountains, Germany, 36156; Ochsenkopf, in the Fichtelgebirge. Germany, 

 36159 ; Gefrees, in the Fichtelhirge, Germany, 36157 ; The Erzgehirge, Germany, 

 36161; Greffenstein, Saxony, 36158 ; Isle of Elba, Italy, 36160; Mount Pleasant, 

 Camborn, Cornwall, England, 36162. 



Biotite muscovite granite: Manchester, Hillsborough County, New Hampshire, 36168; 

 Concord, Merrimack County, New Hampshire, 27081 ; Salem, New Hampshire, 

 27895; northwest from Crawford House, New Hampshire, 27868. 



Biotite granite : Near Calais, Maine (pink), 70146; Auburn, Maine, 28539; Brunswick, 

 Maine (with molybdenite) 28815 ; Millbridge, Washington County, Maine, 25966; 

 Craftsburg. Vermont (orbicular granite), 70098; Lyme Station, New London, 

 Connecticut, 260/9; Baltimore, Maryland, 38355; Jones Falls, Baltimore, Mary- 

 land (with microline), 36751; Ilchester, Maryland (with allanite), 69550; David- 

 son College, Mecklenburgh County, North Carolina, 27644 ; Buckhovn Falls, Har- 

 nett County, North Carolina, 27653; Burnet, Texas, 38824; Buffalo, Jefferson 

 County, Colorado, 36883 ; Iron Mass Mountains, Gunnison County, Colorado, 



