338 PROF. W. AMALTTSKT ON PERMIAN [Aug. 1 895, 



f 



after a closer study of the lamellibranchiata from the Karoo 

 formation, might perhaps prove to be of value for instituting a 

 parallel between the homotaxial deposits of the Russian Permian 

 and the Karoo system of South Africa. 



My recent studies of some lamellibranchiata from the Beaufort 

 Beds of the Karoo system of South Africa, kindly placed at my 

 disposal by the staff of the British Museum of Natural History 

 (David Eraser collection from Bedford, and fossils from the shales 

 at Kimberley), and of those in the Museum of the Geological 

 Society of London (Bain and Rubidge collection from Graaf Beinet), 

 enable me to state that they are extremely like those from the 

 Permian freshwater deposits of Russia. 



Prom the Karoo system (Beaufort Beds of Graaf Beinet) of 

 South Africa, the following lamellibranchiata were described by 

 Daniel Sharpe : 1 Iridina (?) rhomboidalis, Iridina (?) ovata, Iridina, 

 sp., and Cyrena, sp. Prof. T. Rupert Jones 2 has described Cyrena (?) 

 negleeta from the village of Balfour on the right bank of the 

 Kat River, north of Graaf Reinet. After the study of the above- 

 mentioned paleeontological material I have defined the following 

 forms : — 



I. Group of Palceomutela Inostranzewi. 



1. Palceomutela rhomboidalis, Sharpe (Beaufort Beds, Graaf 

 Reinet). 



2. Palceomutela ovata, Sharpe (ibid.). 



II. Group of Palceomutela Keyserlingi. 



3. Palceomutela, cf. Keyserlingi, mihi (ibid.). 



4. Palceomutela, n. sp., aff. orthodonta, mihi (Shales at Kimberley 

 Diamond Mines). 



5. Palceomutela trigonalis, mihi (ibid.). 



6. Palceomutela, n. sp., aff. Golowkiaslciana, mihi (ibid.). 



III. Group of Palceomutela Verneuili. 



7. Palceomutela semilumdata, mihi (Beaufort Beds, Graaf Reinet). 



IV. Group of Palceomutela Murchisoni. 



8. Palwomutela Murchisoni, mihi (Beaufort Beds, Bedford). 



9. Palceomutela plana, mihi (Beaufort Beds, Graaf Reinet). 



V. Group of Palceanodonta Fischeri. 



10. Palceanodonta subcastor, mihi (ibid.). 



11. Palceanodonta olcensis, mihi (ibid.). 



All these groups and the following species— Palceomutela Key- 

 serlingi, P. trigonalis, P. semilunulata, P. Murchisoni, P. plana, 



1 Trans. Geol. Soc. ser. 2, vol. vii. (1852) p. 226. 



2 Geol. Mag. 1890, p. 410. 



