(Figs. 32-37)

Material examined. Holotype ♂, pharate paratype ♂, RUSSIA, Primorje, little spring seeps on the banks of Lazovska reka ca 50 km W of Lazo * 43°28'N, 133°44'E +, 13.6.1998, leg. P. Zwick. Some larvae taken together with the males are probably conspecific. Presently in coll. Zwick, Schlitz.

Adult habitus. The teneral specimens are typical of genus Nemoura and possess no distinctive traits, apart from the genitalia. The front wing is 7.2 mm long.

Male. Subgenital plate normal, with slender ventral vesicle and short pointed tip resting between the paraprocts. Paraproct transverse, short, apex bifid. The short medial lobe is narrow and separated from the broad external lobe by an angular notch (Fig. 32). Cercus in lateral view (Fig. 34) basally straight, apically regularly downcurved, sclerotization ending in two widely separate short points. Medially from them appears the large bulbous setose apex which is membraneous. In ventral view (Fig. 32) the cercus gently tapers from the base to a neck-like section supporting the large apex resembling a bird head. The caudal end of the dorsal sclerite and the outer point together appear as a narrow caudal edge. In dorsal view (Fig. 33) appears an indistinct mediocaudal point, in addition to the two lateral points. In caudal view (Fig. 35) the sclerite forms a flat cap over the cercus tip and both the mediocaudal point and the external caudal point are seen.

The epiproct is oval, a little restricted anteriorly from midlength (Fig. 36). The narrow ventral sclerite bears about 10 slender spines. The rod-like apical sclerite extends forward but does not reach beyond the general contour of the epiproct. The sclerite's apex is rough, basally from it the tips of two outwardly directed straight spines are exposed. Apical sclerite and looped sclerite stand at a right angle to each other and are connected in a regular curve. The looped sclerite forms an oval ring.

Female. Not known.

Diagnosis. Paraproct and cercus resemble N. gemma, and details of the apical sclerite have also some resemblance. However, in N. gemma the epiproct contour is almost rhomboid. Its apical sclerites are obliquely connected to the looped sclerites and form a cone projecting far beyond the epiproct apex.

Etymology. The name refers to the township of Lazo after which the beautiful stream along which the types were collected is named.