40 CALIFORNIA ACADEMY OF SCIENCES. 



The author remarks in regard to Calymene spinifera: "Among the 

 specimens of Lower Silurian fossils of Missouri in the collection of my 

 friend J. N. Nicollet, Esq., I noticed the tail of this curious trilobite, which 

 has on the back of one of the articulations of the middle lobe an erect 

 curved spine, curved towards the caudal extremity, and more than one- 

 third of an inch in length." 



Conrad's species should replace Cyphaspis girardeauensis Shumard, 

 1855. 



Observations on the lead-bearing limestone of 



Wisconsin, and descriptions of a new genus of Trilo- 

 bites and fifteen new Silurian fossils. 



In Proc. Acad. Nat. ScL, Phila., vol. 1, 1843, p. 329. 

 Thaleops n. g., T. ovatus n. sp. 



Corda (A. J. C.) and Hawle (Ignaz). Prodrom einer 

 Monographic der bohmischen Trilobiten. 



In Abhandl. bohm. Gesell. Wiss., Prag, vol.5, 1847, pp. 129-292, 7 pis. 



This work is generally attributed to A. J. C. Corda. The 58 new genera 

 described in this work are arranged by Joachim Barrande, Systeme silurien 

 du centre de la Boheme, vol. 1, p. 39, as follows: 



I. DIVISION. TELEJUEIDES. 



1. Phlysacium ) = H d halus Bari , 



2. Phanoptes J 



3. Crithias 



4. Tetracnemis 



5. Goniacanthus 



6. Enneacnemis 



7. Acanthociiernis \ 



) = Sao Barr. 

 b. Acanthogramma/ 



9. Eudogramma I 



10. Micropyge \ 



11. Selenosema 



12. Staurognius / 



13. Herse 1 



h = Arionellus Barr. 



14. Agraulos J 



15. Conocoryphe } 



16. Ptychoparia = Conocephalus Zeiik. 



17. Cteuocephalus \ 



18. Selenopeltis = Acidaspis Murch. 



19. Polytomurus = Dionide Barr. 



20. Tetrapsellium = Trinucleus Lhwyd. 



21. Phalacroma = Agnostus (in part) Brong. 



22. Selenoptychus = JEgliiia Barr. 



23. Mesospheniscus Agnostus integer Beyr. 



