KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND. 19. N:0 6. 189 



Fam. XIII. SCALARIDiE Broderip. 

 Gen. CALLONEMA Hall. 



1865 Isonema Meek and Worthen p. p. Proceed. Ac. Nat. Sc. Pbilad., 251. 

 1879 Vallonema H.yll. Palreont. N. York vol. V,ii, 50. 



Shell elongate or short and (/lobular, ornamented hy transverse, distantiated lamellar 

 ribs, aperture circular, j'teristoma continuous. 



This genus was established by Hall to include some Devonian and Silurian spe- 

 cies which had to that time been numbered with Isonema, though they rather did not 

 correspond to the definition given to that genus by its authors Meek and Worthen. 

 I follow the subsequent authors who have placed the genus Callonema amongst the 

 Scalaridaj. In Sweden it had already appeared in the Lower Silurian times, as there 

 are fine species of it in the Lepta3na Limestone of Dalecarlia. 



1. Callonema obesum n. 



PL XV fig. 27. 



Shell thick, trochiform, of the same length and breadth, with transverse whorls, 

 broader than high, regularly increasing in size. Whorls five, ornamented with oblique, 

 chordlike, lamellar ribs, directed in a gentle curve, going from the suture backwards. 

 The surface acquires through them a fluted appearance, as these chords are more close 

 together than in the next species, finer and more regular. The aperture and the um- 

 bilical side are destroyed in the only specimen extant. H. 8 mill., br. 8 mill. This 

 specimen belongs to the Museum of the University of Copenhagen, and has been found 

 by Angelin probably in the limestone of Wisby. 



2. Callonema scalariforme n. 



PI. XV f. 24—26. 



Shell elongate, turriculated and slender, of six moderately ventricose whorls. 

 Surface ornamented by obliquely transverse, thread like lamella;, and between them 

 with parallel lines of growth. The aperture is ovate and the lips thin. The lamella; 

 project beneath each other as scales, the younger beneath the older and they may pro- 

 perly be regarded as the edges of successive apertures. H. 15 mill., br. 10 mill. Ano- 

 ther specimen h. 10 mill., br. 5 mill., height of aperture 4 mill. 



Some specimens from the middle limestone of Wisby. 



Gen. HOLOPELLA Mac Coy. 



Syn. 1852. Holopella M.A.C Coy Brit. Pal. Foss., 303. 



1881. Aclisina De Koninck p. p. Faune Carbonif. 11, 3, p. 86. 



Shell elongate, slender, smooth or finely striated, peristome continuous. 



