1891.] LAND-SHELLS FROM BORNEO. 31 



Having seen but one specimen, I at first thought that this shell 

 was only a reversed variety of D. hiigonis, and that the depression 

 was the result of some injury. I now find that Dr. Hungerford has 

 two specimens, and a young shell in Mr. Everett's collection from the 

 Niah Hills is evidently of the same species. 



Dtakia regalis. 



Helioo regalis, Benson, Ann. Mag. N. H. ser. 2, vol. v. p. 215 

 (1850); Reeve, Conch. Icon. pi. xcvi. fig. 526 (1852); Pfeiff. 

 Monogr. Helic. iii. p. 52 (1853), et v. p. 82 (1868) ; id. in Mart. u. 

 Chemn. Conch.-Cab. ed. ii. p. 377, t. cxli. figs. 5, 6. 



Helix vittata, Adams & Reeve, Zool. Voy. Samarang, Moll. p. 60, 

 ph XV. figs. 7 a-c (1850) ; Metcalfe, P. Z. S. 1851, p. 70. 



Ryssota (?) regalis, Wall. P. Z. S. 1865, p. 407- 



Nanina regalis, v. Martens, Preuss. Exped. Ost-Asien, Land- 

 schneck. p. 225 (1867). 



Var. UNicoLOR. 

 N.W. Borneo {Everett). 



Dyakia busanensis, n. sp. (Plate II. fig. 1.) 



Shell discoid, sharply keeled ; umbilicated ; sculpture above 

 finely decussate, produced by rather irregular transverse lines of 

 growth crossed by very longitudinal hair-like strise ; below glassy, 

 no spiral sti-ieE, a ^evi transverse lines ; colour pale ashy white, with 

 a single broad band next to the periphery and suture ; spire low, 

 flatly pyramidal ; apex rounded ; suture a mere thread ; whorls 5, 

 sides very flat ; aperture semilunate, oblique ; peristome thin ; 

 columellar margin oblique, not reflected, very weak. 



Size: maj. diam. 19'0, min. 17'2; alt. axis 6"7 millim. 



Hub. Busan Hills {A. Everett). 



Dyakia janus. 



Helix janus hifrons, Chemn. Conch.-Cab. xi. p. 307, t. 213. 

 figs. 3016, 3017. 



Helix janus, Pfeifi^. Monogr. Helic. i. p. 77 (1848), et v. p. 83 

 (1868) ; Reeve, Conch. Icon. pi. xci. fig. 494 (1852). 



Nanina albersi, v. Martens, Monatsber. Akad. Berlin, 1864, 

 p. 265 ; id. Preuss. Exped. Ost-Asien, Landschneck. p. 224, et xi. 

 fig. 3 (1867). 



Ryssota (1) janus, Wall. P. Z. S. 1865, p. 407. 



Nanina janus, v. Martens, Preuss. Exped. Ost-Asien, Land- 

 schneck. p. 226, t. xi. fig. 4 (1867). 



Dyakia amphidroma. 



Helix janus hifrons, var., Rousseau in Hombr. et Jacq. Voy. au 

 Pole Sud, Zool. V. p. 11, pi. v. figs. 1-3 (1854). 



Helix martini, V^d^.V.Z.'^. 1854, p. 149; id. Monogr. Helic. 

 V. p. 300 (1859) ; Reeve, Conch. Icon. pi. cxciii. fig. 1356 (1854). 



Nanina amphidroma, v. Martens, Monatsber. Akad. Berl. 1864, 



