278 FERUSSACIA, MADEIRA. 



Madeira: Ponta Sao Lourenco (M. Grabham . 



Twenty-four living specimens collected by Mr. Grabham 

 agree in differing from F. terebella as above indicated, and 

 doubtless constitute a distinct race or species. It may, how- 

 ever, be what the Baron de Paiva attempted to define as A. 

 gracilis var. ventricosa. There is also a possibility that laurenti- 

 ana is what de Paiva alludes to as a more ample form of A. 

 leacociana, from this very place Sao Lourengo Point (Monogr. 

 Moll. Mader., p. 106). 



F. iridescens Woll. must be similar, but is described as con- 

 spicuously iridescent. No figure has been published, and the 

 diameter and length of aperture are not given by Wollaston. I 

 have therefore thought it well to suitably define and figure the 

 form from Sao Lourenco, leaving its ultimate status to be de- 

 termined when the characters of the several ill-defined forms 

 mentioned above are ascertained. 



71. F. GRACILIS (Lowe). PI. 39, fig. 20; pi. 40, fig. 32. 



"Shell long-obovate, slender, thin, glass} 7 , glossy, smooth, 

 imperforate. Spire subattenuate, obtuse, more than half the 

 length of the shell. Whorls rather flattened, the suture rather 

 obsolete. Aperture obovate, toothless, columella broadly ex- 

 panded, slightly truncate, tapering into the thin, submarginate 

 lip. Length 2, diam. 1 line, whorls 5" (Lowe). 



Length 4, diam. 1.8 mm. (specimen). 



Porto Santo: Common in some places in the mountains, type 

 loc. Pico Branco; also in the Grand and Southern Desertas. 



Helix gracilis LOWE, Trans. Cambr. Philos. Soc. , iv, 1831, p. 

 61, pi. 6, f. 28. Achatina g., PFR. , Monogr., ii, p. 284. 

 A. g., var. vitrea LOWE, P. Z. S., 1854, p. 200. Glandina 

 gracilis ALBERS, Malac. Mader., p. 56, pi. 14, f. 24, 25. 

 Lovea gracilis WOLL. , Test. Atlant. , p. 250. 



The name vitrea Lowe was applied to the typical form of 

 gracilis, as distinguished from several forms which Lowe con- 

 sidered varieties. 



I have copied on pi. 39, fig. 20, the figure of Albers, which, 

 however, is not very good, being too conic and acute. A typ- 

 ical example from the Wollaston collection is drawn on plate 



