[2] The species was identified by Wise in 1962 as Hydropsyche thomasi, based on a specimen collected by a light trap in Titirangi, Auckland, in 1953.

[1] Wise's original text (the type description) reads as follows: A species close to H. fimbriata McL.

Anterior wing with pale irrorations giving a unicolorous ochreous effect in general view.

Dorsal plate, from the side, with upper angle a rounded protuberance with marginal setae, lower angle produced obliquely downwards in a long point apically, a short inwardly turned point basal to this not visible in side view.

The lower portion of the apex, from beneath, is seen as a wide plate with strongly spinose distal margin, lateral angles not produced basally.