part_of adult Hypostome Basis capituli adult labrum Fig. 7-12, Fig. 7-16, in Biology of Ticks ISBN:0-19-505910-7. Flap like structure covering the roof of the preoral canal. Very short in ixodid ticks but long in argasid ticks and extending over the full length of the preoral canal (hypstomal gutter). In argasid ticks, the labrum can move up and down, thereby separating the blood flowing into the mouth from the saliva expelled above it into the salivarium. In argasid ticks, the labrum is hollow and filled with fluid. This is an adaptation for rapid feeding characteristic of these ticks. TADS:0000039 TADS:0000039 default_namespace