The top surface (carapace) of the White-tailed spider’s cephalothorax (the fused head and thorax) has a distinct marking called a fovea which can be seen in these images. The fovea takes the appearance of a deep, dark, narrow, longitudinal slit connected to a dark circular shape in the centre of the carapace. This feature marks the internal attachment point of the spider’s thoracic muscles that serve the sucking stomach and is apparently one of the key markings used to classify these spiders into their families.