340 LIEUT.-COL. H. H. GODWIN-AOSTEN ON [Juiie 18, 



19. Pterocyclos mindatensis. Bock. 

 Pterocyclos miiidaiensis. Bock, P. Z. S. 1881, p. 634. 

 Near P. loweanns, Pfr., but larger. 



M ^ 20. Pterocyclos niahensis, u. sp. (Plate XXXV. figs, 'i, 3 a.) 



Shell dextral, discoid, very widely, perspectively umbilicated ; 

 sculpture a thick epidermis, crossed by stony Hues of growth ; colour 

 umber-browu, with narrow zigzag markings crossing the whorls at 

 regular intervals ; apex not raised above the succeeding whorls ; 

 suture shallow ; whorls 5, subangulate at the periphery, with a 

 raised rib upon it, two similar less defined ribs above and three on 

 the underside ; aperture circular, very oblique ; peristome double, 

 inner continues simple, the outer much expanded and reflected, par- 

 ticularly on the upper margin, where it forms one strong sutural fold, 

 which a very slight further development would convert into a tube, 

 it then falls over in front forming a frontal lappet, with sinuate 

 edge. 



Size: maj. diam. 27"75, min. 23*0; alt. axis 5'5 ; body-whorl 

 11"5 millim. 



Operculum dark brown, multispiral, with coarse raised edges in 

 front, deeply concave below. 



Hab. m&hUWls {A. Everett). 



This species is very like P. cucullus at first sight, but its keeled 

 and ribbed whorls and the very different form of the winged expansion 

 of the peristome separate it. 



A shell very similar occurs in the Molu Hills. It differs in three 

 particulars, viz. in the form of the wing, being less developed into the 

 tubular form ; in the apical whorls being depressed below the succeed- 

 inc whorls ; in the coloration being of a darker tint with broader 

 zio-zag blotchiugs. This I distinguish as var. depressus. This 

 shell was first found by Mr. Boxall and given to Dr. Huugerford, 

 who presented a specimen to the British Museum, which I have seen. 



Z?,^. 21. Pterocyclos cucullus, n. sp. (Plate XXXV. figs. 2, 2 a.) 



Shell dextral, flatly discoid, very amply and perspectively umbili- 

 cated ; sculpture a thick epidermis with fine Hues of growth ; colour 

 pale sienna, with broad flame-like zigzag markings crossing the 

 whorls transversely ; apex perfectly flat ; suture impressed ; whorls 

 nearly 5, rounded, rather rapidly increasing ; aperture oblique, 

 circular ; peristome double, the inner continuous, simple, the outer 

 sharply reflected and increasing in breadth on the outer margin, and 

 the upper, where it droops over into a cowl-like shape, having one 

 single depression or fold. 



Size : maj. diam. 26*0, min. 22-0 ; alt. axis 5'5 ; diam. ap. 



8" 5 millim. 



Operculum very dark brown, multispiral, with raised edges. 

 Hab. Niah Hills. 



Pterocyclos eudcedalus, Crosse, Joura. Conch, xvii. 1869, p. 187. 

 Hab. Borneo. 



