340 PROF. W. AMALITSKT ON PERMIAN [A-Ug. 1895, 



IridinaCi) ovatct, Lridina{?), sp., Lridina{?), sp., Cyrena (?). This 

 sandstone, which consists of casts of lamellibranchs, resembles in 

 external appearance and other characters the rock developed near 

 Nishny-Novgorod in the upper horizon (B) of Permian marls and 

 sandstones. Among these shells it was easy to recognize forms of 

 the group Palceomutela Inostranzeivi, but I am unable to give a 

 more definite description, as I had to deal with casts only, though 

 one impression, showing the irregularly striated hinge-margin so 

 very typical of Palceomutela, was well preserved. I was very glad to 

 find the original from which Sharpe made his drawing of the multi- 

 dentate hinge of Iridina (?). These teeth are small and very 

 irregular, though on Sharpe's drawing they appear quite regular. 

 There are a great many small casts, undoubtedly identical with 

 Russian forms from the same deposits, but unfortunately in a bad 

 state of preservation. Some of these small casts belong to the 

 groups : Palceomutela Keyserlingi (very like the species P. ovalis, m.) 

 and Palceomutela Murchisoni (very like the species P. Icevis). 



B. Locality marked. South Africa : Karoo Desert. 



Some pieces of a dark calcareous shale containing shells with 

 external sculpture and hinge-margins preserved. Prom this shale I 

 cleared off some shells, which proved to be Pcdceanodonta (Naiadites) 

 subcastor, mihi, and Palceomutela semilunidata, mihi. The first is 

 found on the Russian horizons B and C, and the second on the 

 horizons C and D of Permian marls and sandstones near Nishny- 

 Novgorod. 



C. Locality marked. Karoo Series : Graaf Beinet. 



The same calcareous shale containing Palceanodonia {Naiadites) 

 okensis, mihi, and Palceomutela, cf. Keyserlingi, mihi, both of 

 which forms are found on the horizons B and C of the Upper 

 Permian marls and sandstones near Nishny-Novgorod. 



D. Locality. Bloemkop, near Graaf Reinet. Collector, Dr. Ru- 

 bidge, 1857. The rock similar to that before mentioned. On the 

 label is written the following : Unio (?) with Phyllotheca (?), Tylo- 

 pteris. This Unio I determine as Palcecmodonta {Naiadites) okensis, 

 mihi. 



E. Locality. At the village of Beaufort on the right bank of the 

 Kat Piver. Collected by Mr. A. G. Bain. Two pieces of greenish- 

 grey calcareous shale with many small lamellibranchiata, some of 

 them being described by Prof. T. Pupert Jones (Geol. Mag. 1890, 

 p. 410) as Cyrena (?) neglecta. Perhaps some of these shells can 

 be referred to the group of Palceomutela Keyserlingi, and especially 

 to the species subovalis. 



2. Through the kindness of Prof. T. Rupert Jones I have been 

 able to examine six small lamellibranch-casts belonging to the 

 Mineral Department of the British Museum (Natural History) 

 numbered 66550, having a label which runs as follows : — ' Karoo 

 Shales, Diamond Mines, Kimberley, South Africa.' Prof. T. Rupert 

 Jones informed me that these shales belong to the lowest horizon 

 of the Karoo Beds at Kimberley. It was easy to recognize among 

 these forms, especially those with a well-preserved external 



