Small larvae, up to 3 mm long.
Antenna short, less then 1/2 mandible length, 5 segmented, with segment 3 shorter than 4 and 5; last 3 segments short. Ring organ in basal 1/3. Striated blade arising from apex of 2nd segment, extending beyond apex of flagellum; accessory blade and Lauterborn organs not visible. Style as long as segment 3.
SI nearly palmate, with stronger lateral tooth and 5 additional median teeth, remaining S setae simple and fine. Labral lamellae absent. Chaeta media serrate, other chaetae simple, spinulae absent. Pecten epipharyngis of 3 scales, each subdivided to give about 8 teeth, with indications of another row of vestigial teeth; chaetulae laterales simple, 3 strong and sclerotised, 4-5 very weak and unsclerotised. Chaetulae basales simple, pointed. Premandible with 2 well-developed apical teeth and 1 inner tooth; brush absent.
Mandible with apical tooth shorter than combined width of 4 inner teeth, apical inner teeth free, innermost fused to mola. Seta subdentalis triangular. Seta interna slender, of 5 nearly smooth branches.
Mentum with median tooth divided and higher than 4 pairs of lateral teeth; outermost lateral more or less deeply divided, giving impression of 5 pairs of lateral teeth. Ventromental plate small, visible only over 2-3 lateral teeth; beard absent.
Anterior parapods fused for most of their length, with numerous groups of minute claws, and some longer, mostly smooth claws. Procercus apparently absent, but vestigial tubercle with 1 short seta may represent procercus. Posterior parapods well developed, with strong apical claws. Body without distinct setae
Antillocladius is known from three described species from the Carribean and Appalachians (eastern USA), although evidence is accumulating of a wider southern hemisphere distribution. The first described larva was from a seepage, and adult records suggest this biotope is usual. Suspect Antillocladius larvae are associated with water droplets on tropical tree leaves.