Macrostomorpha taxonomy and phylogeny

The penis stylet is hook-shaped; it is slightly bent in another plane at a point indicated by the arrow. Its walls are not thickened at any particular point. Its distal opening is terminal. p. 53

The penial tube has a slight bend at its proximal end, and a distinct and sharp bend at its distal end. The distal tip of the stylet is blunt with a terminal opening. The walls appeared of uniform thickness along the length of the tube. p. 56

The distal opening is terminal and oblique, facing the concave side of the bow. The walls surrounding the distal opening appear to be very slightly thickened. p. 50

The penis stylet is a more-or-less straight tube which diminishes in diameter towards its distal tip; in fact the latter is slightly bent as shown in Figs. 5Band C. The walls of the tube around the distal terminal opening are slightly thickened. p. 54

Penis stylet consists of a funnel about 80-98 micrometer in length in slightly squashed specimens, curved in two planes and with a sub-terminal distal opening, the distal end is blunt and cowl (hood) shaped. p. 253

Eyes 10 x 21 micrometer. The penis stylet is typically in the form of a blunt hook. The walls of the tube around the distal terminal opening are very slightly thicker than the walls in the remaining part of the stylet. p. 52

The eyes are small with an irregular shape with dimensions of 8 to 12 micrometer. The penis stylet has its distal end bent at more-or-Iess a right angle to the main tube. This tip constitutes the thickened wall of the tube. The distal opening is situated at the heel of the stylet. p. 51

Acerose smooth penis stylet, no chitin valve in the surface. Its far-forth end show helical curly form. The penis stylet is like end of injector, opening at outboard part of helical bend. p. 703