part of accessory bulb head of spermatheca secondary spermatheca spider_anatomy diverticle A hollow, blind sclerotized structure of the female genitalia of entelegyne spiders, usually connected by a duct to the anterior copulatory duct. The accessory bulb has several gland pores with cuticular glandular ducts. In occasions the accessory bulb is reduced to the patch of gland pores, without its own lumen or duct. SPD:0000140 anterior section of female genitalia