A corporeal catheter comprising a catheter tube having a distal end to which a bolus is connected. The bolus contains a tip section and a tube connector section between which a bolus passage section is disposed. The bolus passage section has a passage therein which communicates through a radial port area with the outside of the generally tubular shaped bolus. The port area includes a port mouth which is elongated between opposed elliptical curved surfaces defining a concave arch. Opposite the concave arch port mouth, under the port is a convex stiffening arch on the bolus and axially aligned with it.
