Both Pseudoanthidium jacobii and P. canariense share the same overall structure of specialized hooked and waved hairs on their metasomal sterna (S3-S4-S5) in males, as well as their dark brown to black apicolateral combs on each lateral arm of S5. The present photo illustrates the structure in a male P. jacobii where S3 also exhibits a short, dense, velvety pubescence anteriorly, posteriorly with pre-marginal brush of hairs, hooked at the tips, as well as an underlying comb of thickened, wavy hairs (Photo NJ Vereecken).