The Hon. E. Chitty on the Stoastomidae. 145 



concave outlines. Jfkorls, 4i, moderately rounded, with a mode- 

 rate suture ; last whorl well rounded. Aperture, moderately ob- 

 lique, very moderately expanded and slightly deflected below, semi- 

 circular. Labrum, slightly produced above in a curved line, pecti- 

 nated by about 15 of" the spiral carinoe. Labium, moderately de- 

 tached from the body-whorl, rather serpentine above and much 

 curved to the right below. Uhibilicus, deep and narrow. Labrul 

 lamella, but slightly expanded. Operculum, slightly concave, with 

 about six horizontal raised laniellre, nearly ])arallel above, but con- 

 verging towards the luubilicus below, strong on the labial side, and 

 faintly crossing over the labial side and covering the labium, with, on 

 that side, others intervening. 



Height 0-062, greatest breadth O'OSG, least breadth 0-OG!). 



Named in compliment to E. L. Layard, Esq., late of Ceylon, now 

 Curator of the Museum, Cape Town, Cape of Good Hope. 



Metcalfeia Swiftiana, Chitty. 



Hab. Near Mr. Chamier's, Santa Cruz Park, Saint Elizabeth 

 (unique). 



Form, depressed conic. Colour, pale horn, light brown at apex. 

 Sculpture, 28 irregularly strong and iuequidistant spiral carinue ; on 

 the upper whorls 6. Spire, moderately elevated, with slightly concave 

 outlines. Whorls, 4|, moderately rounded, with a deep suture ; 

 last rather large. Aperture, slightly constricted and very slightly 

 expanded at its margin ; semicircular ; slightly depressed above and 

 slightly expanded below. Labrum, very slightly produced above ; 

 very slightly pectinated externally by, more or less, all the carinae ; 

 smooth and white and shining at its extreme margin. Labium, well 

 detached from body-whorl, on a plane with the labrum ; much curved 

 to the right below and reflected to the left. Umbilicus, deep and 

 narrow. Labral lamella, widely spreading. Operculum, ? 



Height 0-059, greatest breadth 0-087, least breadth 0-0G9. 



Named in compliment to llobert Swift, Esq., of the Island of St. 

 Thomas, an ardent collector. 



Genus VI. Petitia, Chitty, 



Shell, globose discoid, 



Petitia Petitiana, Chitty. See Stoastoma Petitianum, Ad. 

 Ann, Lye. New York, v. u. 2. p. dl ; Contr. Conch, p. 151 ; Cat. 

 Phan. p. 232. 



Hab. Peace River, Manchester. 



Petitia Cumingiana, Chitty. See Stoastoma Cumingianum^ 



Ad. Mon. Stoast. xVd. 1819, p. 9 ; Cat. Than. p. 231. 



Hub. 1 Manchester. 



Note. — If I have the right type of this shell, the operculum, in 

 addition to the "numerous lamellar grains " described by Adams, 

 Ann. t^- Mar/. N. Hist. Ser.3. VoLi. 10 



