242 B. Etheridge,jun. — New Carboniferous Fossils. 



Ifodiola lingualis, Phil., 1 which it very much resembles, M. lithodo- 

 moides may be distinguished by the difference in size, by the convex 

 ventral margin of the former, by the much more bluntly rounded form 

 of the beaks in the present species, and probably finer, closer, and more 

 regular surface ornamentation. M. lithodomoides resembles M. elon- 

 gata, Phil., 2 but is not carinate, and the dorsal margin is not curved. 

 Under the provisional name of Lithophaga lingualis (Phillips) Messrs. 

 Meek and Worthen have described 3 and given two figures of a shell 

 from the Keokuk group of the Illinois and Indiana Sub-carboniferous 

 series, one of which (pi. 19, fig. 1) appears to be very near our shell, 

 if not identical with it, and certainly distinct from Phillips' M. lin- 

 gualis, from which it differs by its more obtuse umbones and 

 straighter dorsal margin, and, as indicated by its describers, by its 

 much greater size. I am supported in this view by the valued 

 opinion of my friend Mr. G. Sharman. M. lithodomoides shows no 

 trace of the radiating lines of Zithodomus dactyloides, McCoy. 



The following are the approximate measurements of the seven 

 specimens before me : — 



1. Length 1 inch 1| lines, width Z\ inches Longnor, Derbyshire. 



2. 





^2 )J 



j j 



2 



„ 3 lines ,, ,, 



3. 



4. 

 5. 

 6. 



M 



)) 



Hi » 



7 2 ;; 



6i „ 





2 

 3 



2* 

 1 



„ 2 „ (broken) „ „ 



„ Trearne House, Ayrshire. 



>> >> )» 

 „ 10 ,, Glen Lora, Renfrewshire 



7. 



)> 



11 „ 



>> 



3 



,, S~ „ Beith, Ayrshire. 



Localities. — Longnor, Derbyshire, in Carboniferous Limestone (3 

 specimens, Coll. Mus. Pract. Geol.) ; Beith, Ayrshire, in Carboniferous 

 Shale (1 specimen, 4 Coll. Edin. Geol. Soc. ; I am much indebted for 

 the loan of this specimen to the kindness of the Society's Curator, 

 Mr. J. Henderson) ; Lora burn, Glenlora, and Lochwinnoch, Ben- 

 frewshire, from Shale resting on the lowest of six Limestones (I 

 am informed by my colleague, Mr. E. L. Jack, F.G.S., that these 

 occupy the position of the lowest or Howrat Limestone, L. Carbon- 

 iferous Limestone group) ; and Quarry, a little north of Trearne 

 House, Gateside, Beith, Ayrshire, from Shale in connexion with the 

 Lower Limestone (Main), L. Carb. Limestone group (2 specimens, 

 Coll. Geol. Surv. Scotland, collected by Mr. A. Macconochie). 



Pisces. 

 Genus Petalorhynchtjs, Agassiz. 



The peculiar palatal tooth represented by PI. VIII. Figs. 3 and 4, was 

 obtained, with another specimen, by Mr. James Bennie (after whom 

 I beg to name the species) at Shiells Quarry, near E. Kilbride. I was 

 for some time in doubt as to the proper genus to which the two 

 specimens in Mr. Bennie's collection should be referred, and was in- 

 clined to regard them as perhaps typical of a new genus, for which 



1 Geol. York, 1836, vol. ii. p. 209, t. 5, f. 21. 



2 See p. 210, t. 5, f. 24. 



3 Geol. Rep., Illinois, vol. iii. p. 536, t. 19, f. 1 and 2. 

 i Presented to the Society by Mr. Armstrong. 



