IvONGL. SV. VET. AKADEMIENS UAN])L. BANJ). 19. N:0 6. 37 



of Gastropoda from Gotland, But 23 remain, when seven are su|)i)resscd as jjartly dupli- 

 cates *) and partly depending on misapprehension of the German terms of Helmehsen "). 

 These real species are in the main the same as given by MuuCHisoN, Helmeksen and 

 Schmidt and need not again be enumerated. 



Finally in a small paper »Noniina fossilium siluricorum Gotlandia-" published in 

 1867 I gave the names of 23 Gastropoda, but in reality there are only 19, as Eu. 

 cornu arietis nuist be united with E. discors, E. supra angulatus with Inach. angu- 

 latus, Inachus costatus removed to the Cephalopoda and Acroculia sulcata united with 

 A. cornuta. The remaining 19 are: 



Name in the present 

 memoir. 



Macrocheihis sp. = Pleiirotora. valida n. 



Turbo stn'atus His. = Cvcloiiema striatum His. 

 Trochus sp. = Tr. gotlaudicus n. 



Euomph. alatus = Pleur. alata AV.\hlenb. 



Eti. diseors = Oriostoma discors Sow. 



Eu. cequilaterus = Pleur. sequilatera Waul. 



Eu. catemdatus = Or. rufiosura Sow. 



Eu. subsuk-alus = Or. globosum Schloth. 



Eu. funatus = Or. lloeraeri n. 



Inachus angulatus = Or. augulatum Wahl. 

 In. sulcatus = Pleurot. planorbis His. 



Fleurot. lalteala = Pleuiot. labrosa Hali,. 



Ilolopella = Lo.xonema sinuosum Sow. 



Murchisonia citigulata = M. compressa p. p. 

 Murchis. attcnuata His. The saine. 

 Trochita ealyptrata = Autodetus calyptratusScuRENK. 

 Acroculia cornuta His. = Platyceras coruutum His. 

 Bellerophon dilatatus = Tremanotus lougitudiualis u. 

 iSiibuiites sp. = S. veutricosus Hall. 



To these must be added one more, viz. Theca sp., which was regarded as a 

 Pteropod, but is identic with Platyceras enorme, and tliiis the number of species known 

 in 1867 amounts to 20. 



At the outset of this work only 20 or at the highest 23 species thus were known. 

 The great increase is due chiefly to the material which had been accumulated during 

 a long series of years in the Pala3ontological department of the Swedish State Museum 

 of Natural History at Stockholm and the main part of information and most of the ori- 

 ginal types for the figures have been derived from that collection. But in preparing my 

 work I have also been fortunate enough to have received contributions from many in- 

 stitutions and naturalists who have lent me specimens or whole collections for study and 

 in other respects rendered me much valuable information. Prof. Walmstedt and Dr G. 

 Holm have sent me all specimens I wanted from the Cabinet of the University of 

 Upsala, Prof. Lilljebokg has given me free access to the Marklinian Collection in his 

 charge; the late lamented Dr G. LiNNAKSsoN, his successor Dr A. Tullbeug and Hr 

 VON ScHMALENSEE have kindly lent me specimens from the Geological Survey of Sweden ; 



-) Acroculia sulcata, Euomph. catenulatus, E. cornu arietis, Nat. iuHata, Murchisonia articulala. 

 ^) BiGSBY did not see the meaning of Helmeksen, when the latter in his lists has »Turbo (Steiukern)" etc. 

 and BiGSBY wrote uTurbo Steinkcrni" and even »Euoiupii. Stinkerui». 



