SYSTEMATIC 141 



Chlanidota signeyana n.sp., PL VIII, figs. 34, 35 



The species is closely allied to the South Shetlands elongata but is constantly broader and of ovate 

 rather than cylindrical outline. 



Shell thin and fragile, white, covered with a thin, pale buff epidermis. Spire tall for the genus, 

 0-56 height of aperture. Whorls sculptured with moderately strong but narrow sharply raised spiral 

 cords, ten to eleven on penultimate and twenty-three to twenty-six on the body-whorl, plus a few weak 

 intermediates. Surface crossed by dense exceedingly fine axial growth lines. Anterior canal deeply 

 notched ; fasciole margined above by a sharply raised narrow ridge. 



Height 38 mm. ; diameter 24-5 mm. (holotype). 



Height 32 mm.; diameter 21-0 mm. (paratype). 



Height 29 mm.; diameter 19-0 mm. (paratype). 



Height 32 mm.; diameter 19-0 mm. {elongata, St. 1952). 



Height 28 mm.; diameter 16-5 mm. [elongata, St. 1952). 



Fig. F. Chlanidota signeya?ia, n.sp. View of the whole animal with the mantle cut and folded back. Note the vestigial operculum, 

 in relation to the size of the aperture (shown by crossed lines to the left). 



Dentition. Fig. L, 74, p. 194. Operculum. Fig. N, 129, p. 196. The central tooth has a wide 

 but comparatively shallow base, deeply excavated below. 



Animal. The external features of the animal are shown in Fig. F. 



Type locality. St. 167. Off Signy I., South Orkneys, 6o° 50' 30" S, 46 15' 00" W, 20 Feb. 1927, 

 244-344 m - 



St. 162. Off Signy I., South Orkneys, 6o° 48' 00" S, 46 08' 00" W, 17 Feb. 1927, 320 m. 



Chlanidota paucispiralis n.sp., PI. VIII, figs. 36, 37 



Shell small, thin and fragile, narrowly ovate, white, covered with a thin buff epidermis. Spire tall 

 for the genus, o-6 height of aperture. Whorls sculptured with a few wide-spaced prominent but narrow, 

 sharply raised, spiral ridges, four on penultimate and eleven on the body-whorl. Surface crossed by 

 dense, exceedingly fine axial growth lines. Anterior canal deeply notched ; fasciole not margined above 

 by a ridge. 



Height 22-1 mm.; diameter 13-5 mm. (holotype). 



Dentition. Fig. L, 77, p. 194. The radula is almost identical with that of elongata. 



Operculum. Typical, horny, ovate, with apical nucleus; very small. Aperture of shell 3-6 times 

 height of operculum. 



