207 



Diam. ± ; alt. ^ poll. Liberia. Dr. Perkins. 



A singular shell, whose form and texture would lead us to pro- 

 nounce it a Helix. But its small number of whorls, and the state- 

 ment of Dr. Perkins that the animal is very large and sluggish, so 

 that it cannot retract within the shell, would bring it more properly 

 within this genus. The sculpture of its upper and lower faces distin- 

 guishes it. 



Helix indecorata. T. parva, tenui, orbiculato-depressa, arete 

 uinbilieatfi, nitida, glabra, virescente ; spira depresso-convexa, anfr. 

 5£ convexiusculis, ad suturam bene impressam marginatis ; subtus 

 convexa ; apertura lunatil, labro acuto. 



Diam. f ; alt. i poll. Hab. Liberia. Dr. Per!: ins. 



A very plain species, resembling in form small specimens of H. 

 ligera ; but in the characters of surface and umbilieation it is more 

 like a diminutive H. inornata. The whorls revolve more closely in 

 the same space, and form a more dome-shaped spire than the incip- 

 ient whorls of II. pellucida. 



Helix cere a. T. parvula, vix perforata, fragili, deprcsso-orbicu- 

 lari, lucida, nitida, albido-straminea ; spira depresso-conica, anfr. 5 

 convexiusculis ad suturam marginatis ; apertura lunata ; labro acuto. 



Diam. 4 ; alt. \ poll. Hab. Cape Palmas. Dr. Perl ins. 



Very similar in its characters to the preceding, but is less than 

 half its size, of a very different color, and the umbilical region 

 differs considerably, especially the reflection of the lip at that part, 

 which does not cover the portion of the umbilicus next the aperture, 

 but turns round at right angles to it. It may be compared to H. 

 alliaria, but the umbilic is not half as large. The animal is glossy 

 black and extremely active. 



Helix talcosa. T. parva, tenui, vix perforata, pyramidali. 

 talcosa, spiraliter acutissime lirata, basi glabra; spira conica, anfr. 7 

 planis, ultimo acutissime carinato ; apertura rhomboideo-lunata. 



Diam. |- ; axis, f . Hab. Cape Palmas, on bark of trees in forests. 

 Dr. Perkins. 



Remarkable for its trochoid form and silvery lustre, on account of 

 which it would most likely be pronounced a marine species. H. 

 Tbuensis accords well with this, excepting that the sharp revolving 

 lines, about three or four on each whorl, are not mentioned. 



Bulimus mucidus. T. solidula, ovata, mamillata, indentata 

 granuloso-striata, flavida, longitrorsum strigis interruptis nigris ornata ; 

 spira ovali, anfr. 6, supernis ventricosis, ultimo abnormali, contracto ; 

 sutura marginata et crenulata ; apertura parva, rotundato-hinata ; 

 labro acuto, pallido ; columella subtruncata* ; fauce nigro et luteo 

 variegata. 



Axis, If ; lat. | poll. Hab. Interior of Liberia. Dr. Perkins. 



