A X I 



[44] 



ATM 



and to spikes of flowers, proceeding 

 from either of the above situations. 



2. In anatomy, pertaining to the 

 axilla, or arm-pit. 



3. In entomology, applied to parts 

 which spring from the point of 

 union of two other parts. 



A'XINITE. The thumerstein or thu- 

 merstone of Werner. It has ob- 

 tained the name of axinite in 

 consequence of the axe-like shape 

 of its crystals. Its colours are 

 brown, grey, black, and blue. The 

 name of thumerstein was given to 

 it by "Werner, from its having been 

 found near Thum, in Saxony. It 

 occurs massive, often disseminated, 

 but most generally crystallized. 

 Specific gravity from 3-21 to 3-29. 

 Hardness = 6-5 7-0. The 

 crystals are sometimes tabular, and 

 are often so arranged as to form 

 small cells. It is transparent or 

 translucent, sometimes at the edges 

 only, or is quite opaque. Some- 

 times one part of a crystal is violet 

 and nearly transparent, while the 

 other is green and nearly opaque. 

 Texture foliated. Fracture con- 

 choidal. Before the blow-pipe it 

 froths like zeolite, and melts into a 

 hard black enamel. It has been 

 found sparingly in Cornwall, but 

 in no other part of Great Britain. 

 A specimen analysed by Vauquelin 

 was found to consist of silica 44, 

 alumina, 18, lime 19, oxide of 

 iron 14, oxide of manganese 4. 



Some of the porphyritic rocks of 

 Cornwall, says Dr. Boase, are very 

 beautiful, having a violet coloured 

 basis, which appears to be occa- 

 sioned by the compact felspar pass- 

 ing into massive axinite; for the 



latter mineral, in crystals, fre- 

 quently occurs in small irregular 

 veins, which traverse . this rock, 

 after the manner of calcareous spar 

 in limestone. 



A'XINITIC. (from axinite.} Contain- 

 ing axinite. 



A'XINUS. A fossil genus of bivalve 

 shells, described by Sowerby as 



equivalve, transverse ; posterior 

 side very short, rounded, with a 

 long ligament placed in a furrow, 

 extending along the whole ridge; 

 anterior side produced, angulated, 

 truncated, with a fLattish lunette 

 near the beaks. One species has 

 been recorded in the London clay, 

 four in the new red sandstone, one 

 in the magnesian limestone, and 

 one in the carboniferous shale. 

 Lycett. 

 A'xis. (axis Lat.) 



1. The line, real or imaginary, that 

 passes through anything on which 

 it may revolve. 



2. In botany, the imaginary central 

 line of different parts of a plant, 

 round which leaves, or modified 

 leaves, are produced. The stem is 

 also so called, for this reason. 



AXO'TOMOUS. (from agtov, and re/ti/w, 

 Gr.) A mineralogical term, signi- 

 fying cleavable in one particular 

 direction. 



A'YHESTRY LIMESTONE. So named 

 from the village of Aymestry, 

 where it laid open. One of the 

 sub-divisions (the central) of the 

 Ludlow rocks. A sub-crystalline 

 grey or blue argillaceous limestone, 

 a marine formation. 



This sub-division of the Ludlow 

 rocks, says Sir R. Murchinson, is, 

 in the neighbourhood of Aymestry, 

 arranged in beds of from one to 

 five feet thick, dipping to the south 

 and south-east at slight angles; the 

 laminaB of deposit being marked by 

 layers of shells, and sometimes of 

 corallines. When quarried into, 

 the rock is of an indigo or bluish 

 grey colour, in parts mottled by 

 the mixture of white carbonate of 

 lime, both crystalline and compact. 

 In nearly all the quarries between 

 Norton Camp and Aymestry, the 

 rock is charged with a profusion of 

 that remarkable shell called Penta- 

 merus Knightii. This species is 

 confined almost exclusively to the 

 limestone of this sub-division. The 

 following fossils also characterise 



