24 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [June 3, 



moisture, as formerly pointed out by Linnaeus, when he spoke of the 

 Conchistriati and Entrochi of this locality. In the quarries of 

 Bursvik the best sandstones are separated from each other by thin 

 courses of shale, and though they here and there present casts of 

 shells, it is chiefly in the overlying or pisolitic bed that these occur ; 

 viz. Cypricardia retrojiexa^ C. reticulata^ Leptcena lata^ with a beau- 

 tiful Lucina, which seems to have escaped the vigilance of Hisinger, 

 and which we willingly dedicate to that persevering Swedish geolo- 

 gist, who is entitled to much commendation for his various works, 

 geological and palaeontological (^Lucina Hisingeri, Murch. and De 

 Vern.). 



Lucina Hisingeri, 



LuciNA? Hisingeri : a smooth lenticular shell, with the apex inclined rather forward and 

 slightly curved. It is a matter of regret that neither the inner surface^nor the hinge has been 

 seen, consequently the genus is doubtful. 



Between Grotlingbo and Bursvik the sandstone and oolite are not 

 overlaid by any rock, and with the exception of a few large northern 

 blocks and some blown sand, which partially obscure the surface, 

 this barren and treeless district is characterized by its stone walls of 

 sandstone and its pisolitic oolite. 



This external aspect might well indeed have led to a geological 

 mistake ; for anyone who did not examine the fossils and had not 

 learnt their position in the palaeozoic series by comparison with the 

 structure of other countries, might naturally have referred these 

 strata to the oolitic series. The coarser oolite or pisolite of South 

 Gothland is, in fact, scarcely distinguishable from the pea-grit of 

 the inferior oolite of Cheltenham, and the finer-grained rock is 

 mineralogically the same as numerous specimens of the middle and 

 upper oolites of Britain, or of the tertiary oolites of Styria. 



This error was committed by Hisinger, in his general map of 

 Sweden*, and the same author having published a true Jurassic 

 or Lias Ammonite as pertaining to this district, the erroneous view 

 was for a time entertained by other European authors. 



With respect to this Ammonite, we were informed by the best 

 authorities in Stockholm that it was not found in any stratum of ,> 



* Hisinger's petrographical map of Gothland, on tlie contrary, conveys an 

 opposite view, viz. that the limestone is the same from north to south, and di- 

 rectly overlies the sandstone of Bmsvik and Grotlingbo. The latter was there- 

 fore considered by that author to be the fundamental rock of the island, instead 

 of being the uppermost as here represented. 



