490 ANNELIDA. 



stems of which, lying on the surface of mud or sand, have, by their 

 slow decay, given rise to the worm-like markings which we have 

 been here considering. The evidence in favour of this view does 

 not appear to be satisfactory, but it is impossible to pursue further 

 this intricate subject in this place. The student desirous of fuller 

 information on this difficult question may be referred more particu- 

 larly to the important and beautifully illustrated memoir which Pro- 

 fessor Nathorst has published upon the tracks and markings produced 

 by various living forms of Invertebrates. 



LITERATURE. 



i. "A Contribution to the Study of the British Carboniferous Tubicolar 

 Annelides." ' Geological Magazine.' 1880. R. Etheridge, jun. 



2. " Notes on the Annelida Tubicola of the Wenlock Shales." ' Quart. 



Journ. Geol. Soc.,' vol. xxxviii. 1882. Vine. 



3. " Cornulites, Tentaculites, and Conchicolites." Nicholson. ' Amer. 



Journ. Sci. and Arts.' 1872. 



4. " On the Genus Ortonia." Nicholson. ' Geol. Mag.,' Dec. 1, vol. ix. 



1872. 



5. " Ueber fossile Wiirmer aus dem lithographischen Schiefer in Bayern." 



' Palaeontographica,' Bd. xvii. 1867-70. Ehlers. 



6. " On Annelide Jaws from the Cambro-Silurian, Silurian, and Devonian 



Formations in Canada, and from the Lower Carboniferous in 

 Scotland." ' Quart. Journ. Geol. Soc.,' vol. xxxv. 1879. Hinde. 



7. " On Annelide Jaws from the Wenlock and Ludlow Formations of 



the West of England." ' Quart. Journ. Geol. Soc.,' vol. xxxvi. 

 1880. Hinde. 



8. " On Annelide Remains from the Silurian Strata of the Isle of Got- 



land." ' Bihang till K. Svenska Vet.-Akad. Handlingar,' Bd. vii. 

 1882. Hinde. 



9. " Ueber Conodonten." ' Sitzungsberichte d. k. bayr. Akad. d. 



Wiss.' 1886. (Maintaining the view that the " Conodonts" are 

 the jaws of Annelides.) Rohon and Zittel. 



10. " Om Spar af nagra Evertebrerade Djur M. M. och deras Palaeonto- 



logiska Betydelse (On the Tracks of some Invertebrate Animals 

 and their Palseontological Significance)." ' Kongl. Svenska Vet- 

 enskaps-Akad. Handlingar.' 1881. Nathorst. 



11. " Palaeontology of New York," vols. i. and ii. 1843 and 1852. Also 



vol. vii. Suppl. 1888. James Hall. 



12. "Fossils of the Longmynd." Salter. 'Quart. Jour. Geol. Soc.,' vol. 



xiii. 1857. Also 'Mem. Geol. Survey,' vol. iii., Appendix. 1866. 



13. "Vermiform Fossils from the Mountain Limestone." Albany Han- 



cock. 'Ann. and Mag. Nat. Hist.,' ser. 3, vol. ii. 1858. 



14. " The Taconic System." Emmons. 1844. 



15. "The Silurian System." Murchison. 3d ed. 1859. (Description 



of Annelides by Macleay.) 



16. " Petrefacta Germanise." Goldfuss. 1826. 



17. "Ueber ein ^Equivalent der takonischen Schiefer Nord-Amerikas in 



Deutschland." Geinitz and Liebe. 'Verhandl. d. k. Leopold. 

 Carolin. deutsch. Akad. 1867. 



18. " Impressions and Footprints of Aquatic Animals on Carboniferous 



Rocks." Principal Dawson. 'Amer. Journ. Sci. and Arts.' 1873. 



