26 EXOTIC CONCHOLOGY. 



Order— PHYTOPHAGA. 



Family — Helicid^. Shell light turbinated or spiral, the aperture always entire, rarely 



closed by an operculum, and sometimes only rudimentary. 

 Sub-Family — Achatin^e. Shell spiral : aperture oblong or oval, always equal, and 



generally shorter than the spire. 

 Genus — Achatina. Outer lip always thin ; base of the pillar truncated, or siuuated, 



before it joins the outer lip. 

 Sub-Genus — Achatina Proper. Oblong, body whorl ventricose : surface smooth, spire 



variable, outer lip without any lobe. 



A. SULTANA. THE SULTANA SHELL. 



Plate X. 



Testa ventricoso-conica, tenuissima, fragili, diaphana, longitudinaliter et tenuissime striata, 

 olivaceo-fuscescente, lineis rufis, longitudinalibus, flexuosis, confertis, picta : ultimo 

 anfractu, fasciis tribus fusco alboque articulatis, cincto : apertura patula, labro, 

 acuto : spira depressa. 



Helix Gallina Sultana, Chem. 11. tab. 210. fig. 2070, 1. Dihvyn, p. 920. 



Bubinus, Lamarc, 6. p. 117. no. 3. Wood's Cat. Helix, fig. 75. Fav. l.fig. 47. Spix, 

 Test. Braz. p. 9. pi. 9. fig. 11. Ferus. no. 338. pi. 117. fig. 2. 



Shell conic and ventricose, very thin, fragile and transparent, finely striated 

 perpendicularly, of a light olive brown, painted with longitudinally flexuous crowded 

 brown lines, and the last whorl girt with three articulated bands (one of which 

 winds up the spire) of white and brown somewhat crescent shaped markings : aper- 

 ture patulous and ovate : lip acute, spire depressed : length two inches and a 

 quarter. Habitat Guiana and Brazils. 



A. MARGINATA, (VARIETY). MARGINED ACHATINA. 



Plate II. 

 Testa ovato-oblonga, strigis insequalibus ferrugiueis : spira ad apicem obtusa, quinque- 



voluta : sutura depressa, linea sulcata marginali. 

 Zool. Illust. 1st series, pi. 30. Swainson's Malacology, p. 170. List. 579. fig. 34. 



Gualt. 45. B. Knorr, 4. tab. 24. fig. 1. (badly coloured). Sow. Gen. 



Not having seen any shells exactly corresponding with Mr. Swainson's figures, 

 I have extracted his own description from the first series of the Zoological Illustra- 

 tions, premising however that a most distinguished naturalist has assured me that it 

 is by no means a new species, but the Bulla Purpurea of the older writers. This 

 statement Knorr's figure (refered to by Mr. S.) tends greatly to confirm. 



" This rare shell has hitherto been overlooked as a variety of the Linnean 



