Japonia jucunda (E. A. Smith, 1894)
“The white radiating markings which ornament the upper surface of this pretty species stop short at the periphery, leaving the base of a uniform, chestnut tint. The notch in the peristome is slight, but quite evident at the point where the upper margin meets the whorl. Of the four thread-like lirae upon the body whorl, the three uppermost revolve up the spire, and the fourth, which is just below the periphery, passes into the suture and is not seen upon the upper whorls.” (E. A. Smith, 1894)
E. A. Smith (1894) original descriptions on Lagocheilus jucundus – “Testa late umbilicata, turbinata, castanea, lineis albis a sutura radiantibus et angulatis supra ornata; anfractus 5, convexi, sutura subprofunda discreti, liris tenuissimis paucis (in anfr. superioribus 3, ultimo 4) spiraliter cincti, lineis incrementi exilissimis striati, ultimus ad peripheriam acute rotundatus, inferae striis spiralibus parum distinctis sculptus, antice vix descendens; apertura intus albida, circularis; peristoma leviter incrassatum, duplex, superne vix expansum, inferne et prope umbilicum angustissime reflexum.”
Kobelt (1902) descriptions on Japonia (Lagochilus) jucunda – “Schale weit genabelt, kreiseiförmig, kastanienbraun, oben mit weissen Zickzacklinien; 5 gewölbte Windungen mit ziemlich tiefer Naht, sehr fein gestreift, mit 3, letzte mit 4 Spiralreifen, letzte kantig, abgerundet, unten mit feinen Spirallinien, vorn kaum herabsteigend; Mündung kreisrund, innen weisslich; Mundrand leicht verdickt, doppelt, oben kaum ausgebreitet, unten und am Nabel ganz schmal umgeschlagen.”
Lagocheilus jucundus – “Diam. maj. 11 mm, min. 8 mm; alt. 8.2 mm. Apertura 5 longa et lata.” (E. A. Smith. 1902); Japonia (Lagochilus) jucunda – “H. 8.5, Durchm. 11:8 mm.” (Kobelt, 1902); Lagocheilus jucundus – 12.6 mm high, 10.9 mm in diameter with 5 ¾ whorls.” (Solem, 1964)
Type locality – “N. E. Borneo” (E. A. Smith, 1894)
Other localities – “Gomantong Hill” (Solem, 1964); “Bukit Kipangi” (Solem, 1964)