368 DR. WHEELTON HIND ON BRITISH [^Ug. 1899,- 



Ancylus. This I propose chiefly to get rid of the evil of having an 

 unnamed fossil .... and not because I am of the opinion that 

 it really belongs to Ancylus. For, whether it be an entomostracan 

 or a mollusc, the evidence certainly would appear to go towards 

 proving that it had a bivalvular rather than an univalvular 

 carapace.' 



CarbonicoJa Vinti would appear to be the last representative of 

 this well-developed and frequently recurring Carboniferous fresh- 

 water genus, and to occur at a higher horizon than any other 

 species of the genus. As Mr. Kirkby points out is the case in the 

 Durham beds, this fossil is associated in North Staffordshire also 

 with a non-marine fauna. He estimates that Carhonicola ViiUi 

 occurs at an horizon not much over 50 or 60 feet from the top 

 of the Coal Measures or the base of the Lower Red Sandstone, but in 

 North Staffordshire there is a thickness of several hundred feet of 

 red and purple beds of the Upper Coal Measures above the horizon 

 of this fossil, C. Vinti occurring in this coalfield about the middle of 

 the zone of Anihracomya Phillipsii. 



III. On a new species of Ctenodonta from Penton Linns 

 (Dumfriesshire) . 



Introduction. — In pt. iii of my monograph of the British 

 Carboniferous Lamellibranchiata ^ I described a single species, 

 Ctenodonta sinuosa (de Ryckholt), as being the only known repre- 

 sentative of that genus in the Carboniferous rocks of Great Britain. 

 After the work was in print I obtained several specimens of another 

 species which should undoubtedly be referred to this genus, as its 

 hinge-plate possesses no cartilage-cavity between the anterior and 

 posterior rows of hinge-teeth. These specimens occurred in a richly 

 fossiliferous, marine, blue shale, overlain by a massive limestone 

 forming a small gorge, through which the Eiver Liddell rushes. 

 Another thick bed of limestone also occurs below it. The bed of 

 shale is on the Scottish side of the stream and forms a small scar, 

 which is evidently covered by a kind of backwater when the river 

 is high. This shale is slightly inclined ; its surface is covered with 

 fossils and contains a very rich fauna, one which indicates un- 

 doubtedly an estuarine condition. This fauna corresponds to a 

 large extent with that of the shales which occur among the lime- 

 stones of the Lower Limestone Series of the West of Scotland. The 

 following lamellibranchs may be found in this bed : — Nucula gibbosa^ 

 Phill. ; H. Icevistriata, Portlock ; N. undulata, Phill. ; Nuculana 

 attenuata (Phill.) ; Ctenodonta ; Protoschizodus aociniformis (Port- 

 lock) ; Pinna flabelliformis, Martin ; and Edmondia, sp. nov., to be 

 described and figured in pt. iv of my monograph. 



The exact place in the series is doubtful, but the beds are re- 

 ferred to the horizon of the Hurlet Limestone of Scotland by the 

 officers of the Geological Survey. It is probable that these lime- 

 stones are identical with those exposed in quarries at Harelaw Hill, 



1 Palffiont. Soc. vol. Iii (1898) p. 210. 



