206 HELIX §. 44. 



umbilicus mediocris, pervius; apertura securiformis; perist. sim- 

 plex, margine supero antrorsum arcuato, acuto, basali reflexo. — 

 Diam. maj. 14^2, min. 13, alt. 7^2 mill. (CoII. Nr. 31 3.) 

 Helix nigritella Pfr. in Phil. Icon. II. 9. p. 4. Helix t. 6. f. 8 



— — Cheinn. ed. II. Helix N. 6 02. t. 9 4. f. 1 — 4. 

 Habitat in insulis oceani pacifici (Guming). 



Obs. Varial tesla magis minusve depressa , interdum conica (diam. llY^, 

 all. 9 miil.) , umbilico latiore et angustiore. 



538. H. approi&imata Le Guillou.;)^j/^>./^if.^^j;'^3.;/ 



T. discoidea, conico-depressa, umbilicata, carinata, fusca^^ 

 cinereo - lutescente variegata; anfr. 6 — 7 subconvexi, basi de-i 

 pressi, ultimus margine acutus, subtus convexus, radiatim tenui- 1 

 ter striolatus, striis concentricis signatus; spira conico-depressa ; [ 

 umbilicus profundus ; apertura oblique quadrata , incrassata , an- 1 

 terius acuta, superne producta, exteriusque compressa. — Diam.i 

 17,alt. 11 mill. (Guiil.) 



Helix approximata Le Guill. in Revue zool. 1842. p. 139. 

 Habitat in insulis Ternate et Hogoleu. 

 Obs. «Affinis H. exclusae F(5r. » 



539. H. trochiformis Ferussac. . / . <3J2. 



T. urabilicata, solida, trochiformis, apice obtusa, basf ptaha, 

 acute carinata, oblique ruguloso-striata, saturate rufa vel fusco- 

 lutea, nigricanti-fasciata; anfr. 6 supra cariuam prominentem, 

 stramineam convexiusculi ; umbilicus angustus, pervius; apertura 

 irregulariter rhombea; perist. superne simplex, rectum, antror- 

 sum dilatatum , margine columellari recte descendente, subdila- 

 tato, basali reflexiusculo. — Diam. maj. 16^2, min. 15, alt. 9 — 

 10 mill. (CoII. Nr. 314.) 



Helix trochiformis (Helicella) Fer. pr. 301. et Mus. ! 



— — Pfr. Symb. II. p. 40. 



— — Chemn. ed. II. Helix N. 68. t. 1 3. f. 7. 8. 

 CarocoUa circumdata Muhlf. Ant. Verz. p. 40. N. 1*464. 



Habitat in insulis Taheiti et Opara (Ant.); Isle de France (Fer.) 



540. H. serrula Benson. 



T. anguste umbilicata, subdepressa, subconoidea, corneo- 

 albida, subtus convexa, apice acuta; anfr. 7 supra confertissime 

 radiatim phcati, marginati, marginibus elevatis, ultimus infra 

 laevior, peripheria marginata, serrata; apertura angulato-lunaris ; 



