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



1860 Soleniscus Meek and Worthen p. p. Proc. Ac. N. Sc. Philad., 467. 



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



1880 MacrochilinalD. ibid. vol. 20, 241. 



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

 toward its base and twisted, often so much 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 the inner lip, which, though 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 oldest 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 synonymic. 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. Macrocliilina cancellata n. 



PI. XVm fig. 46—47. 



Shell elongate, bulimoid, terete, with seven much 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 strias, which intersect each other longitudinally and transversally, forming 

 small regular 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 from the hill of 

 Linde and two from Sandarfve. 



2. MacroclLiliiia bulimina n. 



PI. XV fig. 14—16, pi. 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 striae, finer and coarser intermingled. The aperture is elon- 

 gate, the outer lip sharp and thin, the interior 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. 



