Genus Leptopsyllus (Leptopsyllus) T. Scott, 1894

Updated genus diagnosis.

Paramesochridae . Body cylindrical, depressed dorsoventrally; with distinct separation between prosome and urosome; rostrum fused with cephalothorax. Caudal ramus with 5-7 setae. Antennule 7- or 8-segmented in female, subchirocer in male. Antennary exopod 1-segmented (except for L. (L.) dubatyi, 2-segmented) with 3-5 setae. Maxilla with 3 endites on syncoxa; endopod 1-segmented. Maxilliped with elongate basis; endopod 1- or 2-segmented. P1 biramous, 2-segmented endopod and exopod. P2 uniramous; without endopod; with 3-segmented exopod, except for L. (L.) abyssalis with 2-segmented exopod. P3 uniramous; without endopod, except for L. (P.) arcticus with 1-segmented endopod; with 3-segmented exopod, except for L. (L.) abyssalis with 2-segmented exopod. P4 biramous; with 1-segmented endopod; with 3-segmented exopod, except for L. (L.) abyssalis with 2-segmented exopod. P1-P4 armature formulae:

Exopod of P5 armed with 3 setae in both sexes.

Sexual dimorphisms in A1, P5, P6 and genital segment.

Type species.

Leptopsyllus (Leptopsyllus) typicus T. Scott, 1984

Additional species.

L. (L.) paratypicus Nicholls, 1939; L. (L.) reductus Lang, 1948; L. (L.) harveyi Wells, 1963; L. (L.) elongatus Drzycimski, 1967; L. (L.) dubatyi Soyer, 1974; L. (L.) abyssalis Becker, Noodt & Schriever, 1979; L. (L.) platyspinosus Mielke, 1984; L. (L.) punctatus Mielke, 1984; L. (L.) celticus Bodin & Jackson, 1987; L. (L.) pundius sp. n.; and L. (L.) koreanus sp. n.