302 a. Ethendge,jun. — New Carboniferous MoUusca. 



Goldfuss has figured in liis " Petrefacta Germaniee " two shells 

 closely allied to P. Soioerhii. One, P. striolat'us, from the transition 

 limestone of the Eifel, has the re-entering angle formed by the ears 

 and the general characters of onr Carboniferous species, but with 

 longitudinal striee in the place of concentric lines.^ The other, dis- 

 tinguished as P. PhilUpsii, from the Greywacke of the Glatz 

 district, Silesia, possesses concentric lines,^ and altogether shows a 

 great resemblance to P, Sotverbii. 



In their description of P. Valdaicus, Count Keyserling and M. de 

 Verneuil point out the affinity borne by their shell to P. tenuistriatus, 

 Miinster, from the German Muschelkalk ; if not identical, the sheila 

 are very closely allied. 



In the elevation of the ears above the general periphery of the 

 shell, P. Soioerhii approaches some Oolitic Fectens (McCoy). If we 

 are to regard the present shell other than, as a true Peeten, it appears 

 to me that Klein's genus Amusium is the correct resting-place for 

 it, as placed by McCoy. Tate describes the latter in the fol- 

 lowing words: "Shell nearly equivalve, gaping in front and behind; 

 smooth outside, generally marked with radiating lines inside."^ 



In nearly all cases where I have examined casts or decorticated 

 specimens of P. Soioerhii, the V-stri^ appear as hollow grooves, im- 

 parting the idea that they had been caused by the decomposition of 

 some special substance entering into the composition of the shell, 

 of a more destructible nature than its chief constituents. 



In a specimen from a shale of the Second Kingshaw Limestone, 

 near Carluke, I have distinctly seen the cartilage pit in the hinge 

 nnder the beaks. 



The distinguishing characters of P. Soioerhii are undoubtedly t^e 

 general form and surface ornamentation, form and position of the 

 ears, and when seen the V-strise. 



Localities and Position. — The chief localities are the following — 

 England: Longnor, Derbyshire (Mus. Pract. Geol.) ; Lowiek, Nor- 

 thumberland (McCoy). — Scotland: Lockridge Quarry , near Stewarton, 

 Ayrshire ; Fernie Hill, near Gilmerton, Edinburghshire, both in the 

 shale of the Main Limestone ; Shield burn, near Benthall, E. Kilbride, 

 in shale bands in ash below Main Limestone ; Teiglam burn, Lesma- 

 hagow, in shale over the Wee Limestone; Cleekhimin Quarry, near 

 Carluke, Thorn Farm Quarry, near Carluke, and Snabe Quarry, near 

 Strathavon, all in shale below the Main Limestone ; Ponfeigh burn, 

 near Douglas, in shale above the Main Limestone ; Calderwater, 

 near Basket Farm, E. Kilbride, in shales of the Crossbasket Iron- 

 stone Series ; Mayfield Ironstone and Limestone Pit, near Carluke, 

 Lochknowe Pit (No. 5), Kingshaw Moss, near Carluke, in shale 

 above the Second Kingshaw Limestone (Geol. Survey Scotland). 

 Carluke,' in Lingida Ironstone (Armstrong and Young). Calder- 

 water, opposite Old Mines of Calderside, and Newfield Quarry, near 

 E. Kilbride, in shale between the First and Second Calderwood 

 Limestones; Burnbrae Old Quarry, near E. Kilbride, in shale below 



1 Plate 160, fig. 7. ^ Md. fig. 6. 



3 EalphTate, in Woodward's Manual of MoUusca, 1868, second edition, p. 412. 



