(Norman, 1869)
Description:
Carapace large, 1.1-1.3 mm long, elongate, lanceolate, compressed, with produced, acutely pointed anterior and posterior extremities. Female slightly larger than male. Fused zone narrow anteriorly, broad ventrally and posteriorly.
Mandible coxa long. Second leg with a chelate knee seta. Fourth podomere of third leg with a strongly spinose anterior margin. Male copulatory appendage with three distal processes: the anterior one elongate, distally bifid, the central and posterior ones lamellar, subtriangular, the central one being the larger. Living specimens colourless or pale brown.
Habitat:
The only living records are from off Scottish coasts in marine, sublittoral waters (50-100 metres depth).
Remarks:
Horne & Whittaker (1985d) showed the genus Xiphichilus Brady, 1870, of which this is the type species, to be a junior synonym of Paradoxostoma. The large size and lanceolate shape of P. tenuissimum make it easily distinguishable from other British members of the genus.
Distribution:
British Isles; and it appears to inhabit deeper water than most other Paradoxostoma species.