4 io SCIENCE PROGRESS. 



Note on "The Geology of the Sahara". — Since the 

 article on the Sahara was written, the fossils collected by 

 Overweg near Bir-el-Hassi, and described by Beyrich, 

 have been subjected to a second critical examination by 

 Freeh. 1 The <>eneral conclusion that the beds from 

 which they were derived are Devonian remains unaltered. 



BIBLIOGRAPHY. 



(i) Arzruni. Ueber den Colestin von Riidersdorf und Mokkat- 

 tam. Zeitschr. deutsck. geol. Ges., vol. xxiv., pp. 477-483, 

 pi. xx., 1872. 



(2) Arzruni. Unterschung der vulkanischen Gesteine aus der 



Gegend von Abu-Zabel am Ismailia-Canal. [Appendix to 

 No. 5 by Beyrich.] Sitz. K. preuss. Akad. Wiss. (1882), 

 Halbband i., pp. 178-182. 



(3) BAUERMAN, H. Note on a Geological Reconnaissance made 



in Arabia Petraea in the Spring of 1868. Quart. Journ. 

 Geol. See., vol. xxv.. pp. 17-39, pi- G 1869. 



(4) BAUERMAN, H., and FOSTER, C. Le Neve. On the Occur- 



rence of Celestine in the Nummulitic Limestone of Egypt. 

 Ibid., pp. 40-44. 



(5) BEYRICH, E. Ueber geognostische Beobachtungen G. Schwein- 



furth's in der Wliste zwischen Cairo und Sues. [With an 

 appendix by Arzruni, see No. 2.] Sits. K. preuss. Akad. 

 Wiss. (1882), Halbband i., pp. 163-178, pis. iv., v. 



(6) Bonnev, T. G. Note on the Microscopic Structure of some 



Rocks from the Neighbourhood of Assouan, collected by Sir 

 J. W. Dawson. Geol. Mag., Decade III., vol. hi., pp. 103-107, 

 1 886. 



(7) COQUAND. Sur les Gres rouges de la Nubie. Bull. Soc. Geol. 



France, ser. Hi., vol. iv., pp. 159-160, 1875. 



(8) DAMES, W. Ueber eine tertiare Wirbelthierfauna von der 



westlichen Insel des Birket-el-Ourun im Fajum (/Egypten). 

 Sits. K. preuss. Akad. Wiss. (1883), Halbband i., pp. 129-153, 

 pi. iii. 



(9) Dawson. J. W. Notes on the Geology of the Nile Valley. 



Geol. Mag., Decade III., vol. i., pp. 289-292, 1884. 

 Dawson, J. W. Notes on the Geology of Egypt. Ibid., pp., 

 385-393, 439-442, 481-484, 1884. 



1 " Ueber palaeozoische Faunen aus Asien und Nordafrika." Nenes 

 Jahrb., 1895, vol. ii., pp. 47-67. 



