248 



PSrCHE. 



(January— M;lrch 18S5. 



Wurtlicii, Peach, Scuddcr. and Wood- 

 ward, until to-day the nuniher of lorms 

 known from pretcrtiary deposits is nearly 

 as great as those from the tertiary. 



The oldest known are those described 

 by I'age and Peach from the lower old 

 red sandstone of .Scotland — two species 

 belonging to the arcJiipolypoda . In 

 the carboniferous formation the archi- 

 folvpoda culminate, showing a consid- 

 erable variety of generic types distinct 

 from those of the devonian, and embrac- 

 ing nearly thirty species, of whicli by 

 far the greater number come from Amer- 

 ica, and the few remaining ones from 

 Great Britain, with possibly a single 

 species from Germany. Four species, 

 imperfectly known, which have lieen 

 referred to lulus, ami wiiich come from 

 the permian of central Europe may be- 

 long to the archipolypoda. The only 



mesozoic forms known are the Julopsls 

 cretacea of Ileer, from Greenland, 

 which is either an archipolypod or a 

 diplopod (it is impossible to tell which), 

 and the uncertain Geop/iilus proavus 

 of Miinster from Solenhofen, which is 

 probably to be looked upon as a nereiti 

 worm. 



The tertiary species are still known 

 almost entirely from the work of Koch 

 and Bcrendt, and belong entirely to the 

 diplopoda and chilopoda, the larger pro- 

 portion to the former. A few species, 

 however, have been indicated from Aix. 

 a single one described from the brown 

 coal of Rott and one from the Green 

 River deposits of North America. 



The following table presents a view 

 of the distribution of the myriopoda in 

 lime. 



Geolgical distribution of myriopoda. 



The geological history of arachnida, which the order is divisible are rejire- 



as known at the present time, pre- sented in the older rocks, antl these', 



sents some points of interest. Only which are not confined to llie lower 



a portion of the great groups into tvpes, attain a degree of perteclion and 



