326 ANNULOSA. 



have covered the surfaces of beds of mud with vermicular 

 markings." Little weight, however, can be attached to this 

 suggestion, since there is only one existing Lingula namely, 

 the very aberrant Lingula pyramidata which has any 

 power of locomotion in its adult condition ; and we have no 

 right to assume that any of the extinct forms were endowed 

 with this quite exceptional faculty, unless distinct evidence 

 to this effect can be brought forward, the occurrence of 

 markings which might possibly have been formed by Palae- 

 ozoic representatives of Lingula pyramidata not constituting 

 evidence of the required kind. 



LITERATURE. 



1. " Palaeontology of New York/', vols. i. and ii. 1843 and 1852. 



James Hall. 



{ 2. "Fossils of the Longmynd." Salter. ' Quart. Journ. Geol. Soc./ 

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

 1866. 



3. "Vermiform Fossils from the Mountain Limestone." Albany 



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



4. " The Taconic System." Emmons. 1844. 



5. "The Silurian System." Murchison. 3d ed. 1859. (Descrip- 



tion of Annelides by Macleay.) 



6. " Petrefacta Germanise." Goldfuss. 1826. 



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



in Deutschland." Geinitz and Liebe. 'Verhandl. d. K. Leo- 

 pold. Carolin. deutsch. Akad.' 1867. 

 t" 8. "Ueber fossile Wiirmer aus dem lithographischen Schiefer in 



Bayern." Ehlers. 1869. 



9. "Impressions and ^Footprints of Aquatic Animals on Carbon- 

 iferous Rocks." Principal Dawson. ' Amer. Journ. Sci. and 

 Arts/ 1873. 



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



Journ. Sci. and Arts.' 1872. 



11. "On the Genus Ortonia." Nicholson. 'Geol. Mag./ Dec. 1, vol. 



ix. 1872. 



