8 THORKLL & LINDSTRÖM, SILURIAN SCORPION FROM GOTLAND. 



are ripple-marked, and the remains of the marine fauna are generally, at least in Got- 

 land, derived from those animal forms, which have lived near the shore or, at all 

 events, in no considerable depth of water. But until the discovery of this Scorpion 

 nothing was known of the air-breathing land animals of this period. The shape of the 

 body, and the peculiar articulation of the tail in this specimen are conclusive that 

 it led a life nearly alike to that of its descendants. Like these, the Silurian Scor- 

 pion must have been enabled to recurve its tail forwards över the body and with the 

 sting to murder its victims^). What these may have been we are at present unable to 

 tell, but probably they were, as now, insects, of which we have sure traces in the old- 

 est Devonian strata, and they have even lately been reported from the middle Silurian 

 of France^). It is probable that the peculiar form of the walking lirnbs and the total 

 want of eyes, at least in the Gotland species, may iudicate some difference in habits 

 from those of the Recent Scorpions, and may be connected with a raore burrowing 

 mode of existence in the Silurian specimens. 



There cannot remain the least doubt that Palasophonus furnishes strong evi- 

 dence in support of the evolution theory, whilst at the same time from the many 

 features in which it resembles the recent Scorpions it swells the ranks of Huxlet's 

 »persistent forms». Though, however, it agrees, in so many particulars, with the Car- 

 boniferous as well as with the more recent Scorpions, it entirely differs from both in 

 the shape of the walking limbs, and these organs became totally changed before the 

 appearance of the Carboniferous Scorpions. But on this point we have dilated more 

 in detail further on in the third section, on the affinities of Palajophonus with other 

 Scorpions. 



') Mr Peach says, Nature JYs 796 p. 298, that »recent scorpions feed extensively on the eggs of various 

 Invertebrates". In all the works on them, from- De Geer to Brehm, which have been accessible to us, 

 insects and spiders are the only food mentioned. The Rev. O. P. Cambridge in his paper on Arachnida 

 in the latest edition of British Encyclopedia says: »it is said to feed on eggs of insects and spiders». 



^) Ch. Brongniart, Sur la découverte d'une empreinte d'Insecte dans les grés Siluriens de Jurques (Calva- 

 dos), Comptes Rendus, 26 Dec. 1884 p. 1164. 



