Figs. 4a–d

Variations on types 2-2-1, 1-3-1 and 1-4. Scale-bars: 50 μm.

a. Type 2-2-1 with rays 2 and 3 apposed for much of their length. Ex: Stilestrongylus freitasi Durette-Desset, 1968a. After Durette- Desset (1968a), modified.

b. Type 2-2-1 with rays 2 and 3 grouped from the base in a narrow V-shape. Ex: right lobe of Stilestrongylus andalgala Digiani & Durette-Desset, 2007. After Digiani & Durette-Desset (2007), modified.

c. Type 2-2-1 with rays 2 and 3 grouped from the base in a wide V-shape. Ex: Carolinensis kinsellai (Durette-Desset, 1969). After Durette-Desset (1969), modified.

d. Type 1-3-1 with rays 3 diverging distally to rays 5 from the common trunk of rays 3 to 5. Ex: right lobe of Heligmonina wakelini Durette-Desset, Digiani, Mahlaba & Behnké, 2007. After Durette- Desset et al. (2007), modified.

Figs. 4e–i

Atypical patterns. Scale-bars: 50 μm.

e. Type 1-1-2-1. Rays 2 arise first from the common trunk of rays 2 to 6; rays 3 are completely separated and parallel to rays 2 and arise at the same level as rays 6; rays 4 and 5 are the last to diverge. Ex: left lobe of Cordicauda cordicauda (Durette-Desset, 1966). After Durette-Desset (1966), modified.

f. Type 1-3-1 t 4-1. Ray 6 arises first from the common trunk of rays 2 to 6; ray 2 arises just distally to the level of divergence of ray 6 and rays 2 to 5 have a short common trunk. Ex: right lobe of Nippostrongylus magnus (Mawson, 1961). Type 4-1. Ray 6 arises first from the common trunk of rays 2 to 6 and rays 2 to 5 have a long common trunk. Ex: left lobe of N. magnus. After Beveridge & Durette-Desset (1992), modified.

g. Type 3-1-1. Rays 5 and 6 arise first but separately from the common trunk of rays 2 to 6 and rays 2 to 4 have a long common trunk. Ex: left lobe of Nippostrongylus marhaeniae Hasegawa & Syafruddin, 1995. The right lobe shows a pattern of type 1-3-1 t 4-1. After Hasegawa & Syafruddin (1995), modified.

h. Type 1-2-1-1. Ray 2 arises first from the common trunk of rays 2 to 6; rays 3 and 4 are grouped and rays 5 and 6 arise separately and at the same level as the group formed by rays 3 and 4. Ex: left lobe of Sciuricola moreli (Gibbons, Durette-Desset & Daynes, 1977). The right lobe shows a pattern of type 2-2-1. After Durette- Desset (1974), modified.

i. Type 1-2-2. Ray 2 arises first from the common trunk of rays 2 to 6; rays 3 and 4 are grouped; rays 5 and 6 have a short common trunk and arise at the same level as ray 2 and the group formed by rays 3 and 4. Ex: right lobe of Trichoslinstowia maseri Durette- Desset & Vaucher, 1974. After Durette-Desset & Vaucher (1974), modified. Type 2-1-2. Rays 2 and 3 are grouped and arise first from the common trunk of rays 2 to 6; ray 4 is isolated; rays 5 and 6 have a short common trunk and arise at the same level as ray 4 and the group formed by rays 2 and 3. Ex: left lobe of T. maseri. After Durette-Desset & Vaucher (1974), modified.