Skenella.] GASTROPODA. 227 



Genus 5. SKENELLA, Pfeffer, 1886. 



Skenella, Pfeffer, '' Die Mollusken von Siid-Georgien," in Jnhrb. d. Hamb. 

 Wissensch. Anstalten, 1886, 96. Type : S. georgiana, Pfeffer. 



Shell depressed, umbilicated ; peristome simple, connected over 

 the parietal wall ; operculum subspiral, with a large process vertical 

 to the nucleus. 



Shell resembling Skcnea in form. 



1. Skenella Pfefferi, Suter, 1909. Plate 13, fig. 20. 



Skenella Pfefferi, Suter, P. Mai. S., viii, 1909, 253, pi. 11, f. 2. 



Shell minute, globosely depressed, thin, pellucid, shining, smooth, 

 umbilicated. There is no sculpture. The colour is amber on the 

 first 2 whorls, light horn on the last whorl. Epidermis very thin, 

 yellowish, slightly polished. Spire conoidal, very low, convex, its 

 height about one-third that of the aperture. Protoconch flatly convex, 

 rather large. Whorls 2| to 3, rapidly increasing, convex, the last 

 not descending, ample, with a regularly rounded periphery ; base 

 flattish, angled around the umbilicus. Suture deep. Aperture large, 

 subcircular. Peristome convex, sharp, thin. Columella vertical, lightly 

 arcuate. Inner lip slightly callous and reflexed, spreading as a distinct 

 callosity over the convex parietal wall. Umbilicus open, about one- 

 sixth of the diameter. Operculum thin, almost colourless, subspiral, 

 the nucleus near the margin, with an elongated subvertical process. 



Diameter, 0-8 mm. ; height, 0-45 mm. 



Animal unknown. 



Type in my collection. 



Hob. Te Onepoto, near Lyttelton, on seaweeds, type (H. S.) ; 

 Lyall Bay (Miss Mestayer). 



Remarks. This species is nearly allied to S. georgiana, PfefEer, 

 from South Georgia, but it is much smaller, the spire more depressed, 

 the parietal callus not so strong, and the aperture not semicircular. 



Fam. LITIOPID^J, Fischer. 



Animal having on each side 3 cirriform epipodial filaments, oper- 

 culigerous lobe with 2 appendages posteriorly ; there is no siphon. 

 Central tooth of radula subquadrangular, devoid of basal denticles ; 

 lateral teeth as in the Rissoidce. 



Shell minute, thin, smooth, plicate or spirally striate. Columella 

 truncated at its base ; operculum horny, spiral. 



Genus 1. DIALA, A. Adams, 1861. 



Diala, A. Adams, A.M.N.H., viii, 1861, 242. Type : D. varia, A. Adams 

 = semistriata, Phil. 



Shell spirally striate, not varicose, sometimes a little nodulous 

 around the middle; columella nearly straight, not truncate; lip 

 simple. 



But few species are known. 



Distribution. Japan, Philippines, Australasia. 



8' 



