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. hugonis, 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. 



DXAKIA REGALIS. 



Helix r eg alls, 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 (1808) ; id. in Mart. u. 

 Cheinn. Conch.-Cab. ed. ii. p. 377, t. cxH. figs. 5, 6. 



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

 pi. XV. fio;s. 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- 

 schueck. 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 striae ; below glassy, 

 no spiral striee, a few 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 milUm. 



Hab. Busan Hills {A. Everett). 



Dyakia janus. 



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

 figs. 3016, 3017. 



Helix janus, Pfeiff, 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 (!) 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, Pfeiff. P. Z. S. 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, 



