— 34 — 



Nur ein Exemplar von Halmahera, tot gesammelt und ohne Deckel, aber doch wohl 

 zweifellos ein Pteroci/dus, der erste Vertreter dieser Gattung von den Molukken. 



2. Pterocyclus tenuilabiatus Metcalfe. 



Cijdostoma temiilabiatum Metcalfe, Proc. Zool. Soc.| London' 1851, p. 71. — Pteroeychis t. 

 Pfeiffer, Monogr. Pneum. I, p. 45. — Reeve, Concholog. icon. sp. 5. — Martens, Ostas. Zool. 

 Moll, p. 114. 



Nur ein verbleichtes Exemplar aus der Minahassa. 



3. Pterocyclus niahensis Godwin-Austen, var. baramensis m. 

 Tafel 4, Figur 1. 



Testa latissime et perspectiviter umbilicata, depressa, fere discoidea, solida, lineis 

 incrementi subcostiforraibus obliquis sculpta, sub epidermide crassiuscula fusca strigis ful- 

 guratis angustis regularibus albis ornata. Spira plana, apice parvo. Anfractus 5 convexi, 

 sutura profunda discreti, regulariter sed celeriter crescentes, ultimus ad peripheriam sub- 

 angulatus, ad angulum lira distincta munitus, supra liris 4 obtusis, aperturam versus dis- 

 tinctioribus cinctus, infra lineis elevatis nonnuUis minus distinctis, dein laevis, ad aperturam 

 leniter descendens. Apertura perobliqua, circularis; peiistoma duplex, internum continuum, 

 porrectum, leviter expansum et subreflexum, lutescens, sulco perprofundo ab externo discretum ; 

 externura magis obliquum, album, tenue, ad suturam sinulum perprofundum fere tubuliformem 

 formans, dein depressum, ad dextram valde expansum et reflexum, ad columellam angustatum. 



Diam. maj. 26, min. 21, alt. 10 mm. 



Pterocyclus niahensis Godwin-Austen, ' Proc. Zool. Soc. London 1889, p. 340, t. 35, fig. 3. 



Gehäuse sehr weit und perspektivisch genabelt, niedergedrückt, fast scheibenförmig, 

 festschalig, dicht und schief rippenstreifig, unter einer dicken, braungelben, leicht gefältelten 

 Epidermis braun mit schmalen, weifsen, ziemlich regelmäfsig gestellten Zickzackstriemen, 



• Shell dextral, discoid, very widely perspectively umbilicated; sculpture a thick epidermis, crossed 

 by strong lines of growth; colour umber-brown, with narrow ziczac inarkiugs crossing the whorls at regulär 

 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 uuderside; aper- 

 ture circular, very oblique; peristome double, inner continuous simple, the outer much expandcd and reflected, 

 particular on the upper margin, where it forms one strong sutural fold, which a very slight further deve- 

 lopment would convert into a tube, it then falls over in front forming a frontal läppet, with sinuate edge. — 

 Size: maj. diam. 27,75, min. 23, alt. axis 5,5, body whorl 11,5 mm. 



