186 



Gresslya abducta. Phillips, sp. 

 PL VIII, flg. 3. 



1829. Unio abdiictus. Phillips, J. Illustrations of the Geology of York- 

 shire. York. p. 156, tab. VI, fig. 4. 



1858. Myacites abduchts. Quexstedt, F. A. Der Jura. Tübingen, p. 325, 

 tab. 44, fig. 17. 



Eight casts of fine-grained brown sandstone from Mount 

 Nathorst resemble exactly the Munich specimens of »Gresslya 

 gregaria , Ziet. abdiida, Phill. sp.», which came from the 

 «brown Jura d» of Laufen near Balingen. 



The largest specimen, a cast, is 54™™ long, 41™" wide and 

 32"^ thick. 



Gresslya abducta is quoted by Qdenstedt from the «brown 

 Jura a». In the Munich Collection there are fragments of the 

 same species from the «brown Jura ^». 



Fox-Strangways M gives them as occurring in the Jurense- 

 zone, Millepore Bed and Cornbrash of Yorkshire, and Woodward ^) 

 quotes them from the Passage Beds, (Jurense- and Opalinum- 

 zones), the Inferior Oolite (Murchisonae-, Humphriesianum- and 

 Parkinsoni-zones) and questionably from the Great Oolite and 

 Stonesfield Slate from Dorsetshire to Yorkshire. 



Gresslya ijeregrina. Phillips, sj). 

 PI. VIII, fig. 4. 



1829. TJnio peregrinus. Phillips, J. Illustiations of the Geology of York- 

 shire. York, p. 144, tab. VII, fig. 12. 



A few casts in a fine-grained brown sandstone from 

 Mount Nathorst resemble very closely the Munich specimens 

 of Gresslya peregrina, which are also casts and were obtained 

 from the «brown Jura d» of Laufen near Balingen. 



The largest cast is 60™™ long, 38™™ wide and 24™™ thick. 



') Fox-Strangwats, C. 1892, p. 61. 

 =) WooD\VARD, H. в 1S94, p. 560. 



