HELIX.— Plate CX. 



Thk Guayaquil Helix. Shell broadly umbilicateJ, 

 somewhat discoid, pale horny, obliquely closely stri- 

 ated ; spire depressed ; whorls six, rounded ; aper- 

 ture lunar-circular; lip simple, sharp. 



I'FtiKFEK, Pro. Zool. Soc. 1851. 



Hab. Babuhoya, Guaya(iuil. 



01' a pale horny but firm texture, marked irregularly 

 with opake white lines and patches. 



Fig. 622. (Mus. Cuming.) 



This shell, originally described under the name of Helix 

 Powisiana, is now referred to the larger one of the same 

 peculiar Nautiloid growth named //. involuta, of which it 

 is supposed to be the young, see PI. CIX. Fig. 612. For 

 Sp. 622 see PI. CXIV. 



Species 623. (Mus. Cuming.) 



Helix orbis. Hel. testa imperforatd, dincoided, virenti- 

 lulesceute, glaberrimd, nitida, pellucidd, supra plana, 

 ■iiiitm conveximcuht, medio impressd ; suturd submar- 

 ginatd ; anfractibm quinque ad sex, planis, ultimo 



penultimo oil latiore, mperni anguUito ; apertiira tub- 

 verticali, laid, lunari ; peristomate recto, acuta, »im- 

 plici. 



The oub Helix. Shell imperforated, discoid, greenish- 

 yellow, verj' smooth, shining, transparent, above 

 Hatteiied, rather convex lieneath, impressed in the 

 middle ; suture faintly margined ; whorls five to six, 

 flat, the last scarcely broader than the last but one, 

 angled at the upper jtart ; aperture nearly vertical, 

 broad, lunar ; lip straight, sharp, simple. 



Helicopsis orbis. Peck, Index, p. 2. 

 Helix orbis, Pfeiffer. 

 Helix plmmtata, Anton. 



Hab. Island of Opara, Pacific Ocean ; Cuming. 



A flat horny species of slowly eidarging growth, not um- 

 bilicated. 



Fig. 624 and 625. (Mus. Cumine.) 



These two figures have been inserted accidentally. The 

 first is H. paludosa, represented in PI. LXIV. Fig. 32a, 

 and the second is H. siitiiralis, PI. LXI. Fig. 301. For 

 Sp. 624 and 625 see PI. CXIV. 



