1974] 
Quintero — Web of Spilasma tubulofaciens 
3ii 
suspension line (Fig. 8) and having a catching web parallel to the 
floor, with an empty segment. 
The numerous repairs in the web of S. tubulofaciens, the thickness 
of the suspension lines, and the elaborate construction of the retreat 
all suggest that this web is long lasting (relative to the life span of 
the spider), and with time is repaired and modified. The retreat of 
the younger female had more space for occupancy than the retreat of 
the older female (as determined by body length as a percent of the 
length of the retreat), the space perhaps serves to accommodate ad- 
ditional growth of the spider without having to enlarge the retreat. 
Additional collections might verify this observation. 
Nielsen (1928, pp. 534 - 535 ) has excellent photographs of Achaea- 
ranea saxatile (Koch), a theridiid, building a similar type of conical 
retreat on the ground and later scaffolding it to the desired height. 
It is likely that a similar (energy saving?) strategy is used by S. 
tubulofaciens, instead of making numerous trips to carry and assemble 
the materials above the ground, although above the ground modifica- 
tions and repairs might be introduced at a later date. 
The adaptive convergence of webs has been discussed recently by 
several authors (see Kullmann, 1972). Strangely, emphasis in their 
discussions has been placed on considering orb webs as indivisible 
entities which appear to have evolved as a unit. Although interac- 
tions must likely occur among the major structural components of 
the web (hub, retreat, and capture threads — snare), my impression 
is that each has distinct adaptations to cope with in response to 
environmental and physiological cues (e.g. the retreat to best hide 
the spider). The selective forces which might bring about evolution- 
ary changes in these components, by selecting particular motor pat- 
terns of the spider, must differ and thus these components have 
evolved as distinct characters, although not totally independent. 
Taxonomic notes 
Spilasma tubulofaciens (Hingston), comb. nov. 
Figures 1-5 
Epeira tubulofaciens Hingston, 1932, A naturalist in the Guiana Forest, E. 
Arnold & Co., p. 366. From Guyana, Essequibo River. Web illustrations, 
pp. 150-153; no type material left. 
Araneus tubulifaciens, Bonnet (1955, Bibliographia Araneorum, 2: 620, 80), 
makes emendation of specific name which is of Latin derivation. 
Records . 2 $ $ (one immature) from French Guiana, Crique Limonade, 
3-4 km S. of Saiil, 21-22.VIII.1972. Adult $ and retreats deposited in the 
MCZ, Harvard collection. 
