Tmeticus rectangulatus Emerton, 1915 (p. 137)
Microcentria rectangulata (Emerton, 1915)
Diplocentria rectangulata (Emerton, 1915)
Parerigone rectangulatus (Emerton, 1915)
Type locality: "Mt. Mansfield, Vt., and Brunswick, Me.".
Microcentria pusilla Schenkel, 1925 (p. 297)
Type locality: not given. Switzerland (as inferred from title).
Note: the taxon Savignia foveata, though synonymized by Wiehle (1960), is in fact not a synonym of the present species (see Erigonoplus foveatus for more information).
Note: there is confusion concerning the identity of two taxa described
by Emerton for both of which he used the species epithet
"rectangulatus/-a". Emerton (1913) described a new species Microneta rectangulata, and Emerton (1915) described another new species Tmeticus rectangulatus. The World Spider Catalogue (Platnik, 2000ff.,
accessed on January 18, 2014) lists Microneta rectangulata (sub
Oreonetides) and Tmeticus rectangulatus (sub Diplocentria) as separate
species, but then also lists the younger name as a synonym of the older
name. The latter is clearly a mistake; both taxa are separate species,
which is already obvious from their original description:
Emerton 1913, p. 217
"Microneta rectangulata. new. 2 mm. long, light orange brown with dark
gray abdomen. The mandibles are thickened at the base as in M. viaria,
and narrow at the tip with a small tooth on the front just below the
thickened part. The palpi have the tarsus comparatively narrow with a
very small spur at the base. The tarsal hook is bent at a right angle,
the outer portion thickened at the corner, but ending in a thin, wide
tip. Figs. 5, 5a, 5b. Pl. II. Readville, Mass., on a fence in the autumn
flight, Nov. 5, 1911".
Emerton 1915, p. 137
"Tmeticus rectangulatus. new sp. A translucent spider 1.5 mm. long,
resembling T. entomologicus from Tyngsboro, Mass., 1911; T. digitatus,
Em., from Ithaca, N. Y., Journal N. Y. Ent. Soc, 1914, and T. acummatus,
Em., from New Jersey, Bulletin Am. Museum, N. Y., 1913. It differs from
these species in the tibia of the male palpus, which is truncate and
has three small teeth across the end. Fig. 4. Pl. I. One male each from
Mt. Mansfield, Vt., and Brunswick, Me.".
The original illustrations (shown below) also show that Microneta rectangulata and Tmeticus rectangulatus are different species:
These images have been copied from the original species descriptions by Emerton (1913), Emerton (1915) and Schenkel (1925)
and were rotated and scaled to achieve maximum comparability. They show
the distal end of the male pedipalp, with the bulb apparatus and the
cymbium. The shape of the cymbium clearly differs between Microneta
rectangulata and Tmeticus rectangulatus (note the lateral outgrowth in
Microneta rectangulata!). In addition, the shape of the paracymbium
differs, it is a angular hook in Microneta rectangulata, whereas it is a
rounded hook in Tmeticus rectangulatus. In conclusion, Tmeticus
rectangulatus is not a synonym of Microneta rectangulata; both are
differentent species. By contrast, the original figures of Tmeticus
rectangulatus and Microcentria pusilla show that both are very similar
and that the synonymization of both names is justified. The shape of the
paracymbium is a rounded hook in both cases and the characteristic
scoop-shape of the cymbium is identical in both taxa. In addition, the
distal end of the tibia shows three protrusions (the third cannot be
seen in Schenkel´s figure, because the pedipalp is viewed from a slighly
different angle than the one in Emerton´s figure, but is described in
the text of the original description).
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