Type locality. Both holotype and paratype were collected from Fen-chi-hu in Jia-i County, central Taiwan (23° 29’31.1”N; 120°41’59.4’E), 1400 m in altitude, gathered from grass slope under leaves.

Holotype. SL: 4.47mm, SW: 4.70mm; APL: 2.21mm, APW: 2.33mm; NMNS 5636-001.

Paratype 1. SL: 4.27mm, SW: 4.49mm; APL: 2.10mm, APW: 2.13mm; ASIZ MLSP 104201401.

Etymology. The name honors the Boonkio (old toponym of Fen-chi-hu), primary habitat of this species.

Description. As genus. Shell (Fig. 6 A–C) small, 4.47 mm in length and 4.7 mm in width. Shell turbinate and conical-globose, with five moderately convex whorls. Shell of red brown color, somewhat pale at periphery.

Surface sculpture of 6–10 indistinct spiral veins crossed by finer growth lines, rendering them somewhat crispate and the interstices minutely pliculate. Shell surface covered with red-brown slightly shiny periostracum and irregular periostracal lamellae. There are two regular rows of periostracal hairs between the sutures, one on the shoulder, one on the periphery. There are seven rows of periostracal hairs under the periphery, increasing in length from the umbilicus to the periphery. The shoulder and peripheral periostracum hairs are 3–4 times longer than basal periostracal hairs. The periostracal hair has a tapering tip. Umbilicus open. The aperture is circular. The outer lip is not reflected. The operculum is translucent ceratoid, a little concave, centred, multispiral with a very thin pellucid edge.

There is an orange red snout between two bluish gray tentacles on the head. The gray foot is covered with two dark gray lobes. (Fig. 7 D)

Remarks. This new species is similar to its sympatric species Japonia formosana (Fig. 6 G–I). But the latter is festucine in color and has spoon-like periostracal hairs (Fig. 8 D) instead of a tapering tip (Fig. 8 C). J. lanyuensis (Fig. 6 D–F) is another analog, but with a rougher periostracum and longer basal periostracum hairs. The present new species is also similar to J. katorii Minato, 1985 from Japan, but the later with one spiral series peripheral periostracum hairs.