( 568 ) 



MoBERG supposing that my Trilubites-remaiiis Avoiild ])rove to belong' 

 to this species, which is not always to l)e (listiiigiiish(Ml from Ai-ioiiellus 

 Primaexiis. 



Indeed, 1 had been thinking of this species, but as Linnarsson declares 

 that here the vaulted part of the mid-shell before the glal)ella towards 

 the outside slopes strongly dowji, 1 thought 1 could not range my 

 remains under this head. The mid-shell 1 received from Lund con- 

 firmed my opinion. 1 informed Prof. Mobero of this and sent him a 

 few plaster-casts of the Trilobites-remains occurring in the erratic- 

 Itlock found at Vries. I was answered that Prof. Moberg shared my 

 opinion and considered them as having come from Arionellus Pri- 

 maevus. At the same time he was so kind as to send me a plaster- 

 cast of the best of the mid-shells of this species of Trilobites, found in 

 the collection at Lund. Now 1 could ascertain that in Arionellus 

 Primaevus the })art of the cephalon in front of the glabella does 

 not turn down, which is not si)ecially mentioned by BrOgger and 

 Linnarsson. 



Also iu the uiid-shell of w Inch ^Ioberg sent me a plaster-cast, the 

 breadth of the glabella diminishes but little tow ards the front, though 

 its length is about 14 millimetres. 



1 think, then, that we now nuxy with certainty conclude, that in 

 the ^'ries erratic-block we tiud remains of Arionellus Primaevus 

 BrOgger. As this Trilobite occurs only in layers that contain remains 

 of Holmia (Olenellus) Kjerulti Linrs, and as these are taken to be 

 the youngest of the Under-Cambrian ones, the age of the layer of 

 which this erratic-block in former times formed part, may be easily 

 determined. 



Besides occurring at Tomteu iu Norway aud at Forsemölla near 

 Andrarum in Schonen, which places I mentioned already, Arionellus 

 Primaevus is probably found in two more places in firm rock, viz. 

 at Kiviks Esperöd to the North and at Gislöfs Hammar to the South 

 of Simrishanm in Schonen. The former place was first made mention 

 of by Nathorst ^), Avho told that he had found there an off-print of 

 an Arionellus? That in Gislöfs Hammar remains of an Arionellus 

 occur, Avas first communicated to ns by Linnarsson, in his description 

 of the Arionellus-remains of Forsemölla. According to this writer, 

 many of the mid-shells found there by von Schmalensee much 

 resembled the larger shells of Forsemölla, which he dared not with 

 certainty call Arionellus Primaevus. 



1) Nathorst. Om de kambriska och siluriska lagren vid Kiviks Esperöd etc. Geol. 

 Föreningens i Stockholm Förhandlingar. Bd. 3. 1877. p. 264. 



