Descriptin of Plate X.

• Fig. 1.Lysiosquilla spinosa. Endopodite of first abdominal appendage of male, posterior side: A, basal joint; B, terminal joint, with outer lobe a, and inner lobe b. (Enlarged.)

• Fig. 2.Terminal joint, B, of same, anterior side: d, retinaculum; e, fixed limb of forceps; f, movable limb of forceps. Other letters as in fig. 1. (Enlarged.)

• Fig. 3. Portion of the retinaculum, highly magnified, showing the curved setæ.