Lewis & Short

sīphuncŭlus, i, m. dim. [sipho], a little pipe from which water springs forth, Plin. Ep. 5, 6, 23; 5, 6, 36.
Also written without the aspirate, sīpuncŭlus, Fronto, Or. 1 med.

sīpunculus, v. siphunculus.