304 R. Etkeridge, jun. — New Carboniferous Mollusca. 



Ohs. — I have ventured to refer Fig. 3 to Phillips's P. ellipticus, 

 notwithstanding the very short description and imperfect figure of 

 the former ; but it appears to me to correspond better with the cha- 

 racters of the species as given by Phillips and McCoy than with 

 any other of our British Aviculopectens. It has great affinities with 

 Pecten Sowerhii, so much so indeed, that were not the ears placed 

 after the usual manner of the genus, instead of at an elevated angle, 

 as in the former, one would be inclined to refer it to that species, 

 more especially when in compressed specimens the grooves from the 

 beaks down the sides of the shell are present, consequent on pressure. 

 The ears are the only portion upon which any ornamentation is trace- 

 able, as the body of the shell is quite devoid of radiating, and with 

 but few and wide apart concentric lines. McCoy mentions the 

 existence of colour markings, dark zigzag on a light ground. Like 

 that of P. Soiverbii, the shell of A. ellipticus was very thin, even 

 more so I imagine, sometimes presenting quite a shrivelled appear- 

 ance. Under the name of P. inornatus (Phil.), McCoy briefly de- 

 scribed ' another species, the characters of which also closely corre- 

 spond with those of the present shell. I have been unable to find 

 Pliillips's original descrij^tion, but McCoy states that the surface is 

 "■ concentrically waved with obtusely rounded, smooth wrinkles." 

 May not the two shells A. (^Pecten) ellipticus and P. inornatus be the 

 same under slightly different aspects ? I have never seen a specimen 

 of P. inornatus, so merely throw out the suggestion. Two specimens 

 of an Aviculopecten have come under my notice presenting the ovate 

 form, and small striated ears of the present species, with the shell 

 removed, showing the V-strise so characteristic of P. Sowerhii. 

 Whether A. ellipticus also had these markings, the materials at hand 

 do not permit me to state with any certainty.^ 



Localities and Position. — Calderwater, near Tower on Calderwood 

 Grounds, near E. Kilbride, Lanarkshire, in shale of the Crossbasket 

 L'onstone series ; Mayfield Ironstone and Limestone Pit, near Car- 

 luke, in shale above the Second Kingshaw Limestone ; Calderwater, 

 opposite Old Mines of Calderside, near E. Kilbride, in shale above 

 the Second Calderwood Limestone, all in the Lower Carboniferous 

 Limestone Group. In the Upper Carboniferous Limestone Group, 

 old quarry near Andershaw, Glespin Water, near Douglas, Lanark- 

 shire, in shale between two beds of Limestone (Geol. Survey Scot- 

 land) ; Teiglam Burn, Lesmahagow (C. W. Peach), in black shale. 



Genus Posidonomya, Bronn (=Posidonia, Bronn). 



PosiDONOMYA coRRUGATA, Etheridge. Plate XIII. Figs. 4, 5, and 6. 



Anomia corriigata, Etheridge, MS. Armstrong and Young's Cat. Garb. Fos. "W. 



Scot., Trans. Geol. Soc. Glasgow, 1871, iii. app. p. 45. (no descrip.) 



Posidonomya eorrugata, E. Eth., jun. Mems. Geol. Sury. Expl. 32, Scot., 1873, p. 103. 



1 Synopsis Garb. Fossils, 1844, p. 94. 



2 My friend Mr. G. W. Peach has lately shown me another specimen of a valve 

 possessing the small ears of this species, and ornamented with the V-strise of P. 

 Sowerhii. I find that in some notes attached to the description of Pernopccten 

 Shumardianus, Winchell, Messrs. Meek and Worthen state that one of them (Mr. 

 Meek) has described, in the " lieport on the Goal-measure Fossils of Nebraska" (a 

 work I have unfortunately not seen), a shell with the hinge-line in one valve straight, 



