DISTINGUISHING THE JUMPING SPIDERS ERIS MILITARIS AND ERIS FLA VA IN NORTH AMERICA ( ARANEAE : SALTICIDAE )

The jumping spiders now identified as Eris marginata are among the most frequently encountered in North America, for they are common on trees, shrubs and herbs throughout much of the continent. However, two species have been confused under this name. One is an abundant transamerican species whose proper name is Eris militaris; the other is Erisflava, widely distributed in eastern North America though common only in the southeast. In this paper I describe how they may be distinguished. The abbreviation MCZ refers to the Museum of Comparative Zoology; ZMB to the Zoologisches Museum, Humboldt-Universittt zu Berlin.

Phidippus molinor Chamberlin 1925: 133, fig.49@.Holotype in MCZ 1? with label "Dendryphantes molinor Chamb., ?holotype, Utah: Mill Creek Canyon, R. V. Remarks on synonymy: It is unfortunate that most workers since about 1930 have accepted without question Simon's (1901" 624) synonymy of Attus militaris Hentz 1845 with Attus marginatus Walckenaer 1837, for the synonymy is incorrect: Walckenaer's orig- inal description (p.466) and Abbot's figure (number 444) clearly refer to Hentzia palmarum (Hentz).Walckenaer refers to an elon- gate abdomen, a fawn-brown first pair of legs, yellow posterior legs, and chelicerae elongate and held in front, whereas Eris militaris has an abdomen of typical width, posterior legs strongly marked with dark brown, and chelicerae robust and divergent.Abbot's drawing (see Figure 1), on which Walckenaer based his description of A. marginatus, unambiguously portrays a male Hentzia palmarum, given that his specimen was from Georgia.Because the name margi- natus is inappropriate for the transamerican Eris species, another name must be used.The type material for the next oldest name, Attus militaris, is apparently lost or destroyed.Burgess (1875, vii) said that only 60 specimens glued on cards remained of Hentz's collections, the remainder having been destroyed.The surviving specimens were in the collection of the Boston Society of Natural History, which has subsequently become the Boston Museum of Science.The Museum of Science no longer has these specimens nor any record of them (D.Salvatore, pers.comm.), nor does the MCZ, which received many of the Society's collections.I presume Hentz's types to have been lost or destroyed.Without the type material the interpretation of Attus militaris is not entirely clear, for Hentz's 1845 description might refer to either the transamerican or the east- ern species.Still, his failure to describe a white marginal band in the male, and his illustration showing a dark femur on the male palp (better seen in his original color drawing) both suggest that he had the transamerican species.Therefore, I have designated a male of this species as neotype for Attus militaris.This is advantageous for nomenclatural stability, for Hentz's name was the only name com- monly used before 1930 for the abundant transamerican species.In contrast, I have been unable to find any use of Koch's names albo- vittatus, aurigera, and humilis since 1864, except in synonymies and catalogues.
Wrinkles on the ventral surface of the embolar base usually straight, and absent from the retrolateral half (Figs. 2, 5, 6; see arrow in Fig. 6).
Each duct proceeds medially to a flower-like structure (apparently gland openings; see arrow in Fig. 4), then posteriorly.
Habitat varied; common on trees and shrubs.Distribution shown in Fig. 14.
While less common than militaris, many males are available in col- lections (including the Peckham and Banks collections), identified as militaris or marginata.Chickering's Michigan collections are mixed E. militaris and E. flava.Though most of Kaston's identifica-  tions were correct, at least some Floridian males he identified as E. marginata prior to his 1973 paper are E. flava.
Male carapace with marginal band of white scales extending across clypeus (Fig. 13) and usually back well past the palps.Longi- tudinal white bands extending back from ALE usually narrower than in militaris.Palp femur and often patella distinctly paler than more distal segments.Embolus longer and thinner than in militaris, arising more abruptly and more directly behind the embolar base (Figs.11, 12).Wrinkles on embolar base, especially the more retro- lateral ones, are distally curled retrolaterally (Figs. 8, 11, 12; see arrow in Fig. 12).Female carapace with patch barren of scales just above the mar- ginal white band at a point below anterior lateral eyes.Epigynal openings wider and face more anteriorly (Fig. 9) than in militaris.
Each duct first proceeds posteriorly and then laterally to the flower- like structure (Fig. 10, arrow), then posteriorly.The epigynal ducts are the best distinguishing feature.
Habitat information is sparse, but the species appears to prefer marshes and fields.Found in cedar swamp (Mass.),sweeping grass and herbs near river (Nebr.), on vegetation in marshy area (Ont.), meadow (I11.), on Nelumbo lutea and in fields (Fla.).Distribution shown in Fig. 15.

Fig. 1 .
Fig. 1.Abbot's figure 444 on which Walckenaer (1837) based his description of Attus marginatus.Abbot's legend reads "444.Aranea.Taken 4th April, two upon a Myrtle on the side of a Pond in the Oak Woods of Burke County.Rare."From a color slide taken by Allen Brady of Abbot's (1792) original in the British Museum (Natural History).

Fig. 15 .
Fig.15.Distribution of Erisflava.The specimen from the North Platte River at Bridgeport, Nebraska was collected by me, and the identification checked carefully.