Tanypus crassinervis Zetterstedt, 1838: 817.
Tanypus signatus Zett. sensu Lundström (1915: 24),?not Zetterstedt, 1850. Material examined. RUSSIA: New Siberian Islands, “Holzgebirge”, 2 ɗ, 23 vi 1903, upper reaches of Wosnessenje River, 2 ɗ, 3–4 vii 1903, M. I. Brussnew.
The genus Procladius Skuse is in need of revision. According to Pinder (1978), however, the present specimens cannot belong to P. signatus (Zetterstedt, 1850) since that species has a cluster of small teeth apically on the phallapodeme lacking in these specimens. P. crassinervis was regarded as a synonym of P. culiciformis (Linnaeus, 1767) by Roback (1971: 175), whereas he regarded P. c h o re u s (Meigen, 1804) as a separate species. According to Kobayashi (1998), however, male genital structures can vary seasonally, with the gonostylus having a longer heel in spring and fall than in summer. Kobayashi regards P. crassinervis as a synonym of P. choreus, but he explicitly identified P. c h o re u s after Edwards (1929), and the latter, according to Roback (1971), was a misidentification of P. culiciformis (L.). Thus, Kobayashi's (1998) " P. choreus " is not necessarily in any conflict with what Roback (1971) had treated under the name P. culiciformis (L.). It is not known why Pinder (1978) did not follow Roback (1971) in the use of the name P. c u l i c i formis (L.), but comparing the two authors' keys suggests that Pinder's " P. crassinervis (Zetterstedt) " is Roback's P. culiciformis (L.). Apparently consistent with this, it seems possible (judging from Kobayashi's work) that in fact there is only a single species in all of this. If so, then the name P. culiciformis (L.) would have priority.