1972] 
Brady — Sosippus 
47 
rangle: PME width 1.38-1.55 mm, PLE width 2.05-2.43 mm, 
POQ length 1. 20- 1. 40 mm. 
Leg IV: femur 7.3-S.6 mm, patella-tibia 8.6-10.3 mm, meta- 
tarsus 7. 5-8. 9 mm, tarsus 3. 3-4.0 mm, total length 26.7-31.8 mm. 
Patella-tibiae: I 7.9-9. 5 mm, II 7.6-9. 1 mm, III 6.5-7-9 mm. 
Color. Female. Pattern illustrated in Figure 39. Face dark 
reddish brown, black in eye region, with white hair at outer lower 
margins. Chelicerae black. 
Carapace dark reddish brown with broad marginal stripes of 
paler orange-brown due to covering of white hair. Pattern of dark 
lines radiating from thoracic groove accented by white hair. 
Dorsum of abdomen dark brown with five pairs of white spots 
connected by white chevrons on posterior half. Venter of abdomen 
bright yellow-orange. 
Legs brown with alternating light and dusky bands. Coxae and 
trochanters bright orange, conspicuously so on ventral surfaces. 
Labium and endites dark red-orange with lighter yellowish dis- 
tal ends. Sternum bright yellow-orange. 
Diagnosis. Sosippus placidus is recognized by its 3-3 posterior 
cheliceral teeth, a striking red-orange ventral surface, and a distinct 
epigynum (Figs. 25-27). It differs from S. ftoridanus , its closest 
neighbor geographically, in number of cheliceral teeth (Table 1), 
color pattern (compare Fig. 39 with Figs. 34-38), and epigynal 
structure (compare Figs. 25-27 with Figs. 10-13, 19-24). Svsippus 
placidus agrees with S. mimus in number of posterior cheliceral 
teeth (Table 1), but is distinguished from that species by its dif- 
ferent color (red-orange ventral surface), distinct epigynum (com- 
pare Figs. 25-27 with Figs. 1-9) and geographic location (Map 1). 
In addition to its morphological distinctness, S. placidus appears to 
have a different breeding season than the populations of S. ftoridanus 
occurring in its vicinity and also different habitat requirements. 
Sosippus placidus was collected in a very dry area of scrub vegeta- 
tion, including Opuntia (Figs. 44-45). This area was represented 
by Red Hill Island during the Aftonian Interglacial (Laessle, 
1958) and the restricted occurrence of this species seems to be 
directly related to its former insular distribution. For an analysis 
of the evolutionary factors that played a key role here, see the section 
on Geographic Variation and Speciation in this paper. 
Records. Florida. Highlands Co.: Archibold Biological Sta- 
tion near Lake Placid, 24 Jan. -4 Feb. 1943 $00 (M. Cazier), 6 mi. 
S of Lake Placid, 12 June 1968 3$$:7oo (A. R. Brady, J. Tooth- 
aker) . 
