KUNGL. SV. VET. AKADEMIENS HANDLING AR. BAND 48. N:0 1. 



19 



B. No keels on the whorls nor around the umbilicus; surface closely and finely 

 reticulated; colour whitish with a margaritaceous lustre. H. 6.5, D. 7 mm. 

 Radula as in the type var. affinis Jeffreys 1883. 



PI. 5 iig. 38. 



C. 2 — 3 prominent spiral ridges on the last whorl, the subsutural one con- 

 sisting of sparse tubercles; 4 — 5 nodulous ridges on the convex base; aper- 

 ture quadrangular; colour yellowish white, somewhat nacreous. H. 6.7, D. 

 7 mm S. infundibulum (Watson 1879). 



PI. 5 fig. 37. 



Farm. Cyclostrematidae. 



I. Radula oo . 1 . (5 . 1 . 5) . 1 , go ; shell solid with strong transverse ribs ; operculum 

 calcareous Moelleria Jeffreys 1865. 



II. Radula oo . . (4 . 1 . 4) . . oo ; shell thin, finely sculptured (or smooth) ; oper- 

 culum corneous Cyclostrema Marry att 1818. 



Moelleria Jeffreys 1865. 



Shell depressed, with longitudinal dense ribs, extending on the base to the 

 umbilicus; this moderately wide, surrounded with about 4 spiral riblets ; colour white, 

 grayish or brownish. H. 2, D. 2.4 mm; Wh. 3 M. costulata (Möller 1842). 



PL 5 figs. 43—47. 



Cyclostrema Marry att 1818. 



Dclphiuoidea Brown 1827. 



I. Surface cancellated by elevated spiral and longitudinal lines (subg. Cyclostrema 

 sensu stricto). 



Shell liiglily depressed, sculptured by spiral lines and denser longitudinal ones: umbilicus very wide, 

 without peculiar peripheric sculpture; colour transparent white. II. 0.'.i; I). 1.4 mm; Wh. 3 



C. areolatum G. 0. Saks 1878. 

 II. Surface spirally striated (subg. Tubiola A. Adams 1864). 



A. Whole surface with microscopical, densely punctured strije; shell depressed, widely umbilicated; 

 distance form apex to the insertion of outer lip (oblique spire height) about of the aperture 

 height; colour shining white. H. 0.8, D. 1.2 mm; Wh. 3 C. millepunctatum FeiEle 1886. 



B. Surface not punctured; usually only the base striated. 



1. Basal striae concentric with or emerging from the umbilicus. 



a. Spire low, depressed; the obhque spire height of the aperture; 

 shell globose; umbilicus moderately wide; breadth of aperture > half 

 the breadth of the shell; surface smooth, only the base with 8—10 

 striae; colour white. H. 2.3, D. 2.5 mm; Wh. 4 



C. basistriatum (Jeffreys M. S.) G. O. Sars 1878. 



PI. 5 figs. 40 and 42; PI. 7 fig. 8. 

 Surface striated all over var. striolata G. 0. Sars 1878. 



Surface finely and regularly striated all over; aperture more expanded than in the type 

 v^its height = 7^' the iieight of the shellj var. profunda Friele 1879. 



