Paramblopusa borealis (Casey, 1906)

[Japanese name: Nise-nokoba-umi-hanekakushi]

(Figs. 21A–D; 22)

Amblopusa borealis Casey, 1906: 355 (original description; type locality: Queen Charlotte Island (Massett)).

Paramblopusa borealis Ahn & Ashe, 1996: 151 (redescription); Ahn & Maruyama, 2000: 364 (characters).

Material examined. Japan: Hokkaidô: 1 male, 1 female, 8 unsexed, Otaru-shi, Oshoro, 18. IV. 2020, S. Hori; 1 unsexed, Otaru-shi, Shukutsu, 4. IV. 2020, Y. Tasaku (cYT) ; 1 male, Hakodate-shi, Toyosaki-chô, 12. IV. 2020, K. Mitsuhashi (cYT) ; 2 males, 2 females, 8 unsexed, 12. IV. 2020, D. Sumikawa & Y. Tasaku (cYT); 1 male, 9 unsexed, Hamanaka-chô, Mochirippu, Mochirippu-numa, 17. IX. 2020, Y. Tasaku (cYT) ; 180 unsexed, ditto, 12. IX. 1999, M. Maruyama (KUM) ; 1 unsexed, Betsukai-chô, Odaitô, 23. VII. 2020, Y. Tasaku (cYT) ; 1 male, Akkeshi-chô, Akkeshi-ko, 3. VIII. 2022, Y. Tasaku (cYT) ; 1 unsexed, Nemuro-shi, Onnetô, 18. IX. 2020, Y. Tasaku (cYT); 10 unsexed, Nemuro-shi, Shunkunitai, 18. IX. 2020, Y. Tasaku (cYT); 24 unsexed, ditto, 11. IX. 1999, M. Maruyama (KUM); 5 unsexed, Samani-chô, Horoman, 2. V. 2023, D. Sumikawa (cYT) .

Diagnosis. This species can be distinguished from other liparocephaline species by the combination of the following characteristics: body slender, head almost circular, abdominal segments III–VII almost parallel-sided (Fig. 21A); eyes present; labial palpus 3-segmented and segment II thinner than I (Fig. 22C).

Habitat. Adults were collected on gravel beaches and under stones on mudflats.

Distribution. Japan: Hokkaidô; Canada; USA: Alaska, Oregon, Washington.