ICONGL. SV. VET. AKADEMIENS HANDL. BAND. 19. N:0 6. 37 



of Gastropoda from Gotland. But 23 remain, when seven are suppressed as partly dupli- 

 cates *) and partly dependiiig ou misapprehension of the German terms of Helmeksen ^). 

 These real species are in the main the same as given by Murchison, Helmersen and 

 ScHMiDT and need not again be enumerated. 



Finally in a small paper »Nomina fossilium siluricorum Gotlandiie» published in 

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

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

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

 A. cornuta. The remaining 19 are: 



Name in the present 

 memoir. 



Macrocheihis sj}- = Pleurotom. valida n. 



Turbo striatus His. = Cycloueraa striatura His. 

 Trochus sp. = Tr. gotlandicus ii. 



Euomph. alatus = Pleur. alata Wahlenb. 



Eli. discors = Oriostoma discors Sow. 



Eu. wquilaterus = Pleur. eequilatera Wahl. 



Eu. catenidatus = Or. rugosura Sow. 



Eu. subsulcatus = Or. globosura Schloth. 



Eu. funatus = Or. Roemeri d. 



Inachus angulatus = Or. angulatum Wahl. 

 In. sulcatus = Pleurot. planorbis His. 



Pleurot. balteata = Pleuiot. labrosa Hall. 



Holopella = Loxonema sinuosum Sow. 



Murchisonia cingulata = M. compressa p. p. 

 3Iu7'chis. attenuata His. The same. 

 T7'ochita calyptrata = Autodetus calyptratus Schrenk. 

 Acroculia cornuta His. ^ Plat}'ceras cornutum His. 

 Bellerophon dilatatus = Tremanotus longiludiualis n. 

 Subulites sp. = S. ventricosus Hall. 



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

 Pteropod, but is identic with Platyceras enorme, and thus 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 Palajontological 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. Lilljeborg has given me free access to the Marklinian Collection in his 

 charge; the late lamented Dr G. Linnarsson, his successor Dr A. Tullberg and Hr 

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



^) Acroculia sulcata, Euomph. catenulatus, E. cornu arietis, Nat. infläta, Murchisonia articulata. 

 *) BiGSBY did not see the meaning of Helmersen, when the latter in his lists has »Turbo (Steinkern)» etc. 

 and BiGSBY wrote »Turbo Steinkerni» and even »Euomph. Stinkerni». 



