Grapiolites. 283 



features. On the same evening, I found the crater on the 

 summit of the western Y, near Aristoteles (see the diagram in 

 our Jan. number), extremely obvious, and the hill itself ap- 

 parently not more than half as high as its neighbour, and 

 casting much less shadow : the W. height of the group of three 

 hills and three craters N. of Y has also a shallow crater upon 

 its summit ,• and the "irregularity" mentioned at that time in 

 the crater B, is found to arise from a ring formed by a subse- 

 quent eruption in its interior ; a very unusual feature in a crater 

 of this size. At moments of best definition, the mountains 

 exhibit plainly, in many places, the rough and spongy character 

 ascribed to them by Chacornac, and the N. slope of Aristoteles 

 is studded in many places with very minute craters, never seen 

 before. 



OCCULTATIONS. 



The astronomical May 1st is remarkable for the occultations 

 of the two planets Venus and Mercury ; the latter of which, 

 however, according to civil reckoning, falls on the 2nd. The 

 dates are, Venus, Ih. 15m. to 2h. 20m. ; Mercury, 22h. 53m. 

 to 23h. 46m. Both being in broad daylight and near the sun, 

 an equatorial mounting is necessary. — 6th. 117 Tauri, 6 mag., 

 8h. 4m. to 8h. 41m.— 17th. o 2 Libras, 6 mag., llh. 57m. to 

 12h. 59m. 



GRAPTOLITES: THEIR STRUCTURE AND SYS- 

 TEMATIC POSITION. 



BY WILLIAM CARRUTHERS, F.L.S. 



Name. The name GrcqAolithus was first employed by Linneeus, 

 in the original folio edition of his famous Systema Natural 

 (1736), for certain natural objects, which he describes as 

 resembling, but not being, true petrifactions. He included in 

 this generic group ruin marble, dendrites, and fucoid and 

 worm markings, but not a single form of the fossils to which 

 the name is now confined. No change is introduced into the 

 genus until the publication of the twelfth edition of the 

 Systema in 1767. The thin folio* of the first edition, with its 

 twelve pages, had been gradually increasing in the various 



* The Stockholm Academy have resolved to reproduce this rare volume by 

 photo-zincography, so that ere long it is to be hoped that the possession of a 

 fac-simile of Linmcus's great work may be within the reach of every student of 

 nature. 



