Smithsonian miscellaneous collections . , frontal aspect, Agelenopsis pennsyl-vanica (C. Koch). 26, Genital bulb, left, as seen from apex of cymbium, A. utah-ana, showing configuration of conductor. 27, Genital bulb, left, expanded anddisplaced mesad, subfrontal aspect, A. pcnnsylvanica. 28, Genital bulb, left, par-tially expanded, subectal aspect, A. pcnnsylvanica. 29, Embolus, right, disarticu-lated, frontal aspect, A. pcnnsylvanica. 30, Embolus, right, disarticulated, reverseside of fig. 29, A. pcnnsylvanica. 31, Genital bulb, right, slightly expanded,mesal aspect, A. pennsylvanica. 32, Gen
Smithsonian miscellaneous collections . , frontal aspect, Agelenopsis pennsyl-vanica (C. Koch). 26, Genital bulb, left, as seen from apex of cymbium, A. utah-ana, showing configuration of conductor. 27, Genital bulb, left, expanded anddisplaced mesad, subfrontal aspect, A. pcnnsylvanica. 28, Genital bulb, left, par-tially expanded, subectal aspect, A. pcnnsylvanica. 29, Embolus, right, disarticu-lated, frontal aspect, A. pcnnsylvanica. 30, Embolus, right, disarticulated, reverseside of fig. 29, A. pcnnsylvanica. 31, Genital bulb, right, slightly expanded,mesal aspect, A. pennsylvanica. 32, Genital bulb, right, slightly expanded, ectalaspect, A. pennsylvanica. (For explanation of lettering see p. 10.) NO. 4 GENITALIA IN SOME AGELENID SPIDERS—GERING 23 The most important function of the conductor is that of couplingduring copulation. The protective function, if it persists at all in theagelenopsids, is negligible. As the haematodocha expands during theinitiation of copulation, the genital bulb is forced out of the Figs. 22-32.—See opposite page for legend. 24 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 121 The initial engagement of the embolic terminus in the females atriumplaces the conductor directly above the coupling cavity in the caudalmargin of the epigynum. It is shown later that the coupling of theconductor with this cavity is one of the most crucial events in agelen-opsid copulation. Continued rotation of the genital bulb apparentlyresults in a locking of the entire male palpus to the epigynum becauseof the tethering membrane, and of the mechanical configurations ofthe conductor, the embolic base, the tegulum, and the medianapophysis. The radix and the embolus make up the embolic subdivision of thegenital bulb. Comstock (1910, p. 173) introduced the terms radixand stipes respectively for the proximal and distal segments con-necting the embolus to the tegulum. He noted (op. cit., p. 181), how-ever, that in the pisaurid type of palpus the radix an
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