The more important features in the morphology of the male urogenital system of Lepitlosiren and Protopterus may be summarized as follows:—

  • 1
    The testis is very much elongated and is divisible into an anterior formative and n posterior vesicular and conducting region.
  • 2
    The posterior part of the vesicular region is connected with the tubules of the hind end of the mesonephros, which serve for the passage of the genital products.
  • 3
    In Protopterus the testis is connected with the kidney only at its extreme tip; in Lepidosiren there is a stories of about half a dozen segmentally arranged vasa efferentia which open into Malpighinn capsules.
  • 4
    In Protopterus the hind genital region of the kidneys is clearly marked off from the rest, and in this region the kidneys are fused across the middle line; in Lepidosiren there is only a slight attempt at this differentiation, and the kidneys of the two sides are posteriorly, as elsewhere, quite distinct.
  • 5
    The Wolffian ducts open in the adult inale by a common (Protopterus) or by two separate (Lepidosiren) papillae into the distal portion of the cloacal caecum, which is morphologically a urogenital sinus formed in ontogeny as a dilatntion of the fused, but originally separate, posterior portions of the Wolffian ducts.