_Male._ Rather smaller than the female, more slender and more pubescent, the pubescence on the face paler. _Hab._ Aru. 6. SPHEX GRATIOSA. _S._ capite thoraceque nigris, abdomine caeruleo, alis fusco-hyalinis. _Male._ Length 10 lines. Head and thorax black; the face densely clothed with pale golden pubescence; the labrum and mandibles highly polished, very smooth and shining; a thin pale pubescence is scattered over the head, pro- and mesothorax, the latter obscurely chalybeous above, shining, and finely and closely punctured, with an abbreviated, deeply impressed line in the middle anteriorly; the posterior margin of the prothorax covered with shining silvery pubescence; the metathorax opake, and clothed with black pubescence; wings fusco-hyaline, the anterior pair darkest towards their base, the nervures dark fusco-ferruginous, nearly black. Abdomen smooth, shining dark blue; beneath, the margins of the segments have a bright, glittering, pale-golden pile. Gen. PELOPOEUS, _Latr._ 1. PELOPOEUS LABORIOSUS. _P._ niger; scapo antice, pedibus petioloque rufescenti-flavis, alis hyalinis fulvo tinctis. _Female._ Length 12 lines. Black, with black pubescence on the head and thorax; the face with a fine cinereous pile; the scape yellow in front; the mandibles smooth and shining. Thorax: the legs pale ferruginous, the posterior femora darkest; the coxae, the anterior and intermediate trochanters, and base of the femora black; wings fulvo-hyaline, the nervures ferruginous; the metathorax obliquely striated. Abdomen slightly shining at the base, with the petiole reddish-yellow. _Hab._ Aru. Gen. LARRADA, _Smith_. 1. LARRADA MODESTA. _L._ nigra; abdomine pilis argentatis fasciato; alis hyalinis. _Female._ Length 6-1/2 lines. Black; the face covered with silvery down; the mandibles smooth, shining, black, and fringed beneath with fulvous hairs, the cheeks silvery. Thorax slightly shining, closely and delicately punctured; the metathorax opake and transversely striated; wings subhyaline, with a fuscous border at their apex, the nervures black. Abdomen slightly shining; the apical margins of the first, second, and third segments with fascia of silvery pile, which is very brilliant in certain lights. _Male_ closely resembles the female, but has an additional fascia on the abdomen. _Hab._ Aru. Gen. LARRA, _Fabr._ 1. LARRA SIMILLIMA. _L._ nigra, pulchre prismatica, maculis fasciisque variis flavis ornata.