Small larvae, up to 4 mm long.
Antenna less than 1/3 length of mandible; 4 segmented; segment 1 as wide as high; segment 2 elongate; segments 3 and 4 short and subequal. Blade extending well beyond apical segment. Lauterborn organs present.
Labrum with SI of unusual structure with deeply incised lobes; remaining S setae simple although there appears to be an extra bisensillum posterior to SIV. Labral lamellae absent. Pecten epipharyngis consisting of 3 small scales. Premandible with 2 apical teeth and broad inner tooth; brush absent.
Apical tooth scarcely longer than combined width of 3 inner teeth. Seta subdentalis a small peg. Seta interna with only 3-4 finely serrate branches.
Mentum with median tooth with projecting nipple; 5 pairs of lateral teeth. Ventromental plate well developed, not extending beyond outer tooth of flattened mentum; beard absent.
Maxilla with tetrahedral lamellae of palpiger distinct. No galear lamellae. Setae maxillaris simple and short.
Body with parapods absent. Anterior 1/3 of body segment 1 with band of spines and few claws on ventral surface. Posterior segment with horseshoe shaped area of claws surrounding 2 short anal tubules; no claws at posterior margin of this area. Procercus absent; 1 very fine anal seta present.
The structure of the SI seta of Parasmittia is distinctive, only likely to be confused with Smittia and Antillocladius, neither of which have the short 4-segmented antenna.
The larvae of Parasmittia has been found in a humus-rich meadow and woodland soil in Germany and heathland in Brittany (France). The genus remains known only from the western Palaearctic.