"This new species commonly attaches to the species of Dendronephthya, D. castanea Utinomi and its allied forms, by the byssus as in the other pterid species at Tomioka, Amakusa. [...] The habitat of this species is also unique in attaching to soft alcyonarians." [Habe, 1960 : 290.]
"Tanabe Bay, Wakayama Pref." [Habe, 1960 : 290.]
Recent.
"Shell rather small for the genus, light yellow to brownish black,
sometimes clouded by the black blotches along the growth lines or
reddish radial rays, oblique. Left valve larger and more inflatedthan
the right. Posterior wing extends backwards, forming the rather shallow
posterior sinuation. Anterior winged area rather small, triangular,
pointed to the anterior end and covered with the rough periostracum, on
which prickly cords radiate from the umbo. In the right valve
antero-ventral margin has a byssal incurvation from which the byssus
comes out. The median area rather smooth, large and elongated
postero-ventrall." [Habe, 1960 : 289.]
"This differs from the allied forms P. brevialata (Dunker), P. cypsellus (Dunker) and P. loveni (Dunker), which are also collected from the same locality, in having the shell not exceeded 30 mm in length even in the adult form, with a short posterior wing, the end of which is shorter than the posterior end of the median area of the shell." [Habe, 1960 : 290.]
"Tomioka, Amakusa, Kumamoto Pref." [Habe, 1960 : 290.]
"Length 28.5 mm, height 16.3 mm, and breadth 9.3 mm (conjoined valves) (type specimen)
Length 29.5 mm, height 19.2 mm, and breadth 8.5 mm (conjoined valves) (paratype specimen)
Length 26.0 mm, height 14.0 mm, and breadth 7.3 mm (conjoined valves) (paratype specimen)
Length 27.8 mm, height 16.9 mm, and breadth 9.2 mm (conjoined valves) (paratype specimen)
Length 21.2 mm, height 12.4 mm, and breadth 5.7 mm (conjoined valves) (paratype specimen)"
[Habe, 1960 : 289-290.]