KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 48. N:0 1. 



17 



< half its breadth; colour of the shell yellowish, grayish or reddish; 

 radula oo . 1 . (6 . 1 . 0) . 1 . cc. H. 10—18, D. 10— 24 mm 



M. groenlandica (Chemnitz 1781). 



PI. 4 figs. 4—27; PI. figs. 14—20. 

 a. Longitudinal short folds at the suture 



var. undulata Sowerby 1838. 

 ß. Spiral riblets coarse and dense var. rudis Mörch 1869. 



Y. A few spiral riblets and a few impressed lines 



var. intermedia Leche 1878. 



0. Smooth, depressed, umbilicus moderate var, lasvigata Mörch 1869. 

 s. Smooth, conical; only with 1 — 2 spiral ribs on the uppermost 



whorls var. Isevior Jeffreys 1865. 



1. Shell depressed, much dilated, umbilicus wide 



var. umbilicalis Broderip & Sowerby 1838. 

 b. Shell with spiral and longitudinal sculpture, the former consisting 

 of strong sparse riblets on the whorls and feebler ones on the base ; 

 the later consisting of dense-set (on the upper whorls more promi- 

 nent) lamellae of growth, much finer than the spiral ridges; a spiral 

 keel usually surrounding the umbilicus; colour grayish or brownish; 

 radula oo . 1 (4 . 1 . 4) . 1 . oo ; median teeth usually with acute cusps 

 and about 5 — 7 denticles on each side. H, 10—25, D. 10 — 26 mm 



M. cinerea (Couthouy 1839). 



PI. 4 figs. 28—37; PI. 5 figs. 1—5; PI. 7 figs. 1—4. 

 Shell depressed conical, whorls rounded, sculptured by low, uniform 

 keels at equal distances ; angular keel indistinct ; umbilical keel ab- 

 sent or well developed ; base often nearly smooth ; median teeth of 

 the radula with broadly rounded cusps and fine and dense (8 — 14) 

 denticles on each side var. striata Broderip & Sowerby 1829 



(= var. grandis Mörch 1857). 



PI. 4 figs. 34—36; PI. 5 figs. 1 — 2. 

 ri. Radula with all teeth well developed (no rudimentary lateral) ; lamellae denti- 

 culated only in the outer margin; formula oo . . (5 . 1 . 5) . . oo ; shell com- 

 pletely smooth, elevated conical; aperture nearly = the spire in height; colour 

 white with a vivid iridescent lustre; central cusps of the median teeth > the 

 lateral denticles. H. 2—4.3; D. 2.2—4.3 mm M. Vahlii Möller 1842. 



PI. 3 figs. 35—40; PI. (1 figs. — 7. 



Solariella Searles Wood 1842. 

 Maclut'i'oplax Friele 1877. 



I. Shell siiiootli or with indistinct spiral grooves, thin; whorls 5, tumid; umbilicus moderately wide and 

 deep; spire pointed; shell light flesh-coloured with a faint tinge of nacreous lustre. H. 6; I). G..'! mm. 

 dladula unknown) S, l.Tvis Friele 188(). 



K. Sv. Vet. Al<a(l. Hiuidl. Band 48. N:o 1, 3 



