KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND. 19. N:0 6. 191 



1860 Sole7iisous Meek and Worthen p. p. Proc. Ac. N. So. Pliilad., 467. 



1879 Duncania Bayle Journ. de Conchyliologie, vol. 19, 35. 



1880 MacrocMUnalD. ibid. vol. 20, 241. 



Shell elongate, bulimoid, terete, aperture ovate, columellar lip considerahly thickened 

 toward its base and twisted, often so vmch that an acute, revolving plait is formed. 



I have ventured to place three species of Gotland Silurian shells within this 

 genus, mostly on acconut of their general habitus. But this position seems also justi- 

 fied through the conformation of tlie inner lip, which, thoiigh not showing such a 

 distinct plait as in some of the Carboniferous species, is evidently tortuous as in many 

 of them and the Devonian ones. 



The oidest authors placed these fossils with Buccinum as Hoenighaus or Bucci- 

 nites ScHLOTHEiM, and of the subsequent names Soleniscus ought to have the priority, 

 as Macrocheilus as well as Plectostylus were already preoccupied. But as this genus 

 according to the revision of White^) contains chiefly species, which, whith their gutter- 

 like prolongation of the superior corner of the aperture, indicate relations with the large 

 division of the Siphonostoma, it can only partly be admitted as synonyraic. Dunca- 

 nia, given by Bayle, had already twice been employed for corals, fossil and recent, 

 and its author consequently changed it into that now prevalent. 



1. Macrochilina cancellata n. 



Pl. XVIII fig. 46—47. 



Shell elongate, bulimoid, terete, with seven rauch convex whorls, the body 

 whorl being nearly of the same length as the spire. The suture is rather impressed 

 in consequence of the globosity of the whorls. The surface is most finely ornamented 

 by minute strise, which intersect each other longitudinally and transversally, forming 

 small i-egular quadrangles. The aperture is elongated and ovate, the outer lip is thin, 

 the inner lip thick and slightly twisted in its central part. There is no umbilicus. 

 Height 30 mill., br. 19 mill. Eight specimens have been obtained fi-ora the hill of 

 Linde and two from Sandarfve. 



2. Macrocliilina bulimina n. 



Pl. XV fig. 14—16, pl. XVIII fig. 48—49. 



Shell elongate, bulimoid, whorls seven, moderately ventricose, body whorl in 

 length equal with the spire. Suture slightly impressed. Surface covered only with 

 rather irregular, transverse striaj, finer and coarser intermingled. The aperture is elon- 

 gate, the outer lip sharp and thin, the interiör one thickened towards the base, slightly 

 twisted and hiding the umbilicus. H. 17 millim., br. 10 millim. Another specimen, 

 h. 25 mill., br. 13 mill. 



') Proceed. Un. St. National Museum, vol. VI, 184. 



