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



15 



B. Radula with fewer (5 — 30) lamellae with falciform apex; lateral tooth of 

 the same form as the median ones or the first lamellie, well developed ; shell 

 often with net-like or granular sculpture Solariella Searles Wood 1842 



(= Machsero plax Friele 1877). 



Gibbiila Risse 1826. 

 1. Whorls flattened, not inflated nor nodulous below the suture. 



A, Shell often pyramidal, narrowly umbilicated with close-set grayish to 

 brownish radiating stripes, often broken into dots, intervals as narrow as 

 the stripes; these extending mostly to the umbilicus; sculpture formed by 

 fine spiral thread-like ridges, of which 11 — 14 on the base, of uniform 

 strength. H. 12 — 20 mm G. cineraria (Linne 1758). 



PI. 3 figs. 4—7. 



B. Sliell depressed, conical but never pyramidal, narrowly umbilicated, with sparse reddish stripes (inter- 

 vals broader than these), extending to the umbilicus, never broken into dots; sculpture formed by 

 coarser ridges, of which 6 — 8 stronger and a few finer on the base; body-whorl with a broad 

 flattened nearly smootli peripheric angular i-idge. IT. 17, D. 20 mm (England) 



G. obli(iuata (Gmelin 1783) 

 (= Trochus umbilicatus Montagu 1803). 

 II. Whorls inflated in their upper part and truncated at the suture. 



A. Shell conic, narrowly umbilicated; whorls not nodulous; colour yellowish or 

 greenish with a brilliant lustre; longitudinal stripes of brown sparse, wavy 

 or zigzag, usually broken up in dots on the base, disappearing toward the 

 umbihcus. H. 10 — 14 mm C4. tumida (Montagu 1803). 



PI. 3 figs. 8—15. 



B. Shell depressed, widely umbilicated; whorls nodulous at the suture; colour 

 yellowish without lustre, variegated by brown dots or irregular and abrupted 

 stripes. H. 11—20 mm (England) G. magus (Linne 1758). 



PI. 3 fig. 3. 



Cjilliostoina Swainson 1840. 

 Zizyphinus Gray 1840. 



I. Radula as in Gibbula (rhachian tooth with broad basal plate); shell granulated 

 by crossing spiral riblets and longitudinal lamellae; colour variegated with light 

 yellowish and darker red or brownish spots or stripes. H. 12 — 18 mm 



C. miliare (Brocchi 1814) 

 (= Trochus millegranus Philippi 1836). 



PI. 3 figs. 16—20. 



IT. Radula typical (rhachian tooth with narrower basal plate); sliell with spiral 

 sculpture only. 



A. Lateral teeth of the radula 5 on each side; whorls flattened with 3 — 5 spiral 

 riblets and 2 stronger on the base; sides of the shell (from apex to base) 

 slightly convex ; colour pale yellowish or reddish with brown dots or stripes. 

 H. up to 28 mm C. conuloide (Lamarck 1822) 



(= Trochus zizyphinus Jeffreys 1865, not Linne 1758). 



PI. 3 figs. 21 --23. 



