100 IIELIX §. 20. 



249. H. fragilis Pft*. 



T. unibilicala, subdeprcssa, tcnuissiina, lactc cornca, obli- 

 fjue costata; anfr. 4 convcxiusculi ; apcrtura magna, subcircularis; 

 pcrist. tcnuc, acutum, ad umbilicum subrellexum. — Diam. maj. 

 9y3, rain. 8, alt. 6 mill. (Coll. Nr. 132. Spcc. max.) 

 Helix fragilis Pfr. in Wlegm. Arch. 1839. 1. p. 350. 



— — PM. Icon. I. 3. p. 51. t. 3. f. 10. 



_ _■ Chemn. cd. II. Helix N. 527. t. 85. f. 10 — 12. 

 Habitat in insula Cuba, ubi prope Matanzas minus frequentem 

 icgi; Retiro, Carolina et Mt. Vernon (Gould). 



Obs. Nonien servari polesl, cum in disposilione syslemalica H. fragilis 

 Hiilt. (Nr. 89.) in genere Naninae enumeranda sit. 



250. H. sincera Adams. 



T. umbilicata, deprcssa, tcnuis, confcrtim costulata, cereo- 

 albida; spira plana; anfr. 4 convcxiusculi , ultimus tercs; umbili- 

 cus latus, pcrspectivus; apertura subverticalis, lunato-circularis ; 

 pcrist. simplicissimum, rcctum. — Diam. maj. 3 '3, min. 3, alt. 

 1^3 mill. (Mus. Cuming). 



Helix sincera Ad. 'n\ Bost. Proc. 18 45. p. 16. 



— — Pfr. Symb. III. p. 67. 



Habitat in insula Jamaica. 



250% H. mutata Gould. f 



T. orbicularis, depressa, tenuis, cerina, infra rotundata; 

 spirae anfr. 4 convexi, nitidi, juniores glabrati, majores supra 

 crassi-striati , subangulati; sutura impressa; subtus glabra, sulcis 

 radiantibus remotis radiatim divisa, umbilico modico perforata ; 

 apertura ampla, lunata, basi subanguiata; labrum simplex. — 

 Lat. '/10, alt. '/20 poll. (G.) 



Helix mutata Gould 1846. Exped. shells p. 19. 

 Habitat prope Rio Janeiro Brasiliae. 



Obs. «Haud dissimilis H. alliariae. Num forsan H. insignis Orb. ?» 



251. H. radiella Ptr. 



T. umbilicata, depressa, sublenticularis , tenuis, utrinque 

 confertim costulata, cornea, strigis crebris undatis, castancis, ad 

 peripheriam latioribus radiata; spira vix elevata; anfr. 5^2 con- 

 vexiusculi, ultimus subangulatus , basi planiusculus ; umbilicus 

 mediocris, pervius; apertura subverticalis, lata, lunaris; perist. 

 simplex, tcnue. — Diam. maj. 4^4, min. 4/2, alt. ^'/s mill. (Coll. 

 Nr. 133.) 



Helix radiella Pfr. in Proc. Zool. Soc. 1845. p. 125. 



