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Salticidae: Diagnostic Drawings Library

by Jerzy Proszynski 1990

 

Euophrys nearctica Kaston, 1938

[Fig. 16]

Euophrys nearctica Kaston 1938c: 187 T. 9 F. 25, 26 (D ) USA, Maine

 Euophrys nearctica: Proszynski 1976: ff. 100,

 

Material:

 1 F "Euophrys nearctica Kaston, 1938. TYPE" "Old Orchard, Me, 26 Aug. 1937.Coll. D. S. Riggs". Coll. MCZ.

 

Measurements:

 CEPHALOTHORAX in mm in % of L cphth.

  F in mm

F in % of L. cphth

Length cphth. 1.70 100 % 
L. e. f. .77  45 %
HEight cphth. .80  47 %
Width eye field at eyes I 1.14 67 % 
Width eye field at eyes III 1.14   67 %
Width of cephth. at e. III 1.21 71 %
Max. w. cphth    
L. flat surf. cphth .25  
L. of ABDOMEN  2.09  
Max. width of ABDOMEN  1.41  

Length of LEGS in mm

 

  F - Leg I F - Leg II F - Leg III F- Leg IV
tarsus .37  .34  .43 .55
metatar .45  .42 .61 .92
tibia  .55 .45 .55 .87
patella .55 .50  .49 .57
femur .86 .76  .98 1.21
Total  of 5 segments 2.78 2.47 3.06 4.12
Total  in % of leg I. 100 % 89 110 148

 

Colour pattern

Remark: There are no clear cut color differences with Euophrys monadnock, these visible may be due to 50 years longer preservation of the holotype of Euophrys nearctica; whilst there are also no distinct differences in size and proportions, the only valid difference is in external structure of epigyne. However, the external differences, especially sclerotized ridge leading to copulatory opening may be not visible of less sclerotized epigyne. The best character should be the details of internal structure of epigyne, however I could not study these on the single specimen known to science .

 

 FEMALE.

Cephalothorax: pure light brown (whilst Euophrys monadnock has some olive greyish hue), slightly lighter dorsally, sides darker, eye field darker brown, presumably black in fresh specimens; dark ventral edge; sparse, minute colorless setae scattered over anterior eye field and part of thorax, in other areas presumably lost; no contrasting color pattern. Abdomen: there is indistinct and irregular pattern of delicate greyish brown network with weak median streak of similar color consisting of a number of fused triangles, followed on both sides (and separated from network) by a chain of light spots - a typical pattern for many Euophrys species and comparable with Euophrys monadnock, in which however the background is much darker and the spots clearly delimited, instead of a network are rather lines of small light spots; sides are lighter; it is not certain to which degree these differences are due to the post-mortem changes and fading during years of preservation. Frontal aspect: eye field and immediate surrounding of eyes I dark, rims of eyes I with indistinct and sparse whitish setae, more visible dorsally, clypeus brown with darker rim, almost bald, with a few inconspicuous dark setae; chelicerae light brownish grey, pedipalps yellow with tarsus and tibia darker yellow. Legs I brown with lateral surfaces of metatarsus, tibia and patella darker, only indistinctly lighter dorsally; tarsus, patella dorsally and femur ventrally much lighter yellow. Remaining legs deep dark yellow. Leg I: metatarsus with two pairs of ventral spines, longer than the segment itself, tibia with three pairs of ventral spines. Ventral aspect:  coxae dark yellow like legs, sternum light brown with darker rim, median area of abdomen behind epigastric furrow uniformly grey, separated by indistinct lighter dots from prey network pattern of sides; surfaces of lung-books strikingly darker, dark grey; they were as dark in Euophrys monadnock where remaining part of abdomen were also as dark. Epigynum resembles E. monadnock, however the spermathecae seems larger in comparison with length of channels and width of their loop; the most striking difference is the course of sclerotized ridge arriving at sclerotized median plate of the copulatory opening directly from behind, after making almost a complete circle (fig. 16), in Euophrys monadnock it makes only anterior half a circle (on preparation it looks like rather one and half a circle) and arrive from side; these details could be seen externally only on well sclerotized epigyne.

 

Source: Proszynski J. 1990p. Taxonomic revision of N American species of Euophrys and Talavera (Araneae: Salticidae). 9-11, fig. 16. [Preliminary trial edition of a few copies for the purpose of soliciting comments from the experts in this field. Copied through the kind support of the Zoology Department, Eastern Illinois University. Charleston, Ill. June 1990]., Put into this Internet monograph from version November 2004 onwards.

Copyright © for the page by J. Proszynski, 2004.