Argilkceous Genus. I3th Specics. Kragg-Stone. LeJke S. 661, (and 1695 ) / Colour, greyilh red, or reddifh grey; exceed- ing porous, the pores oiten filled with various cryltailizations. Ludre, o. Tranfparency, o. Fradture, uneven and earthy. Fragments 2. Flardnefs from 5 to 7. Sp.gr. 2,314. Feels rough and harfli, gives a yellowifh grey (treak. At 138° it melted into a reddifli brovvn porce- Jain mafs. It is found ln the neighbourhood of Belfaft, and there called Kraggfione; it refemblcs the (tone mentioned by Lefke S. 661, by him called a bafalt. It fectns ah'o to be that mentioned by Faujas as the ^th variety of trap, p. t)i. I bis (tone is often mixed with globules of mag- netic iron (tone, which adds conliderably to its fpecific weight, as in the (pecimen Lefkc S. 1233, vvhofe ip. gr. amounts to 2,910. '1 liefe three fpecies, viz. Wacken, Müllen, and Kragg, have been by moft writers confounded with trap, but their colour, fp.gr. and fufibility, fhew they muft be didinguiüied. 141h Species.