The Odonata or Dragonflies of South Africa. 355 



CERATOGOMPHUS riCTus (Si'lys, 1854). 



S. Afr. Mus. : 1 <J, 1 9, Dunbrody (11 . x, 6 . iii, 1912) ; 1 9 , 

 Wutrrvul (ii,x . 1900). Brit. Mus. : 1 <J , Salisbury (xi . 1905, Marshall) ; 

 1 9 , S. Africa (very old specimen). Coll. K. J. Morton : 1 9 , King 

 Williamstown, Cape (4 . i . 1908, Miss Fountaine) ; 1 9 , Stutterheim, 

 Cape (7 . i . 1908, ead). Coll. E. B. Williamson: 2 ? , Princetown, 

 Natal (28 . i . 12 . ii . 1909, G. F. Leigh) . Coll. Ris : 1 ? , Botchabelo, 

 1-200 m. (20 . ii . 1914, H. Junod). 



Yellow at the sides of thorax with a greenish shade ; markings 

 sharply defined, black, dark reddish-brown on thorax. 



<J . No male in good condition for a description or drawing of 

 structural details was available. 



? . Labium whitish, tips of lateral lobes blackish. Labrum, base 

 of mandibles, geuae whitish ; face and frons yellow, the following 

 markings black ; transverse line on suture of labrum and auteclypeus ; 

 narrow sinuate line on anterior margin of postclypeus ; narrow line on 

 nasofrontal suture. Dorsal surface of frons yellow, broadly black at 

 base ; vertex black with a transversely oblong, dull yellowish spot 

 at the ocelli ; occipital plate yellow, narrowly lined with black at free 

 margin. This margin slightly convex with a row of numerous, robust, 

 slightly irregular black spines ; anterior surface slightly concave with 

 a low, transversely oblong central tubercle. Vertex at occipital 

 suture slightly convex, transversely rugose ; more forward a shallow 

 transverse furrow and then a very slightly concave plane, ending in 

 a sharp transverse ridge over the ocelli. Thoracic pattern Plate IX, 

 fig. 7. 



Legs very robust, longer than in preceding species of Onychogomphus 

 and Mesogomphus, the end of third femora just reaching the joint of 

 thorax and abdomen ; femora yellow with black lines, incomplete on 

 third femora ; tibiae black with yellow external lines ; tarsi black. 



Abdominal segments 1-2 moderately extended, 3-8 comparatively 

 robust, cylindrical, 9-10 narrowed. Lateral margins of 8 with broad 

 foliaceous dilatations ; similar dilatations only just indicated on 9. 

 Yellow, with black markings ; dorsolateral bands on segment 2, 

 which include a trilobate median yellow band ; 3-7 lateral bands, 

 interrupted at anterior end of each segment, including a small yellow 

 spot at each posterior end ; narrow terminal ring ; mid-dorsal line 

 narrowed posteriorly and slightly dilated at transverse carina. On 

 segment 8 lateral bauds dilated in middle to touch each other in 

 mid-dorsal line ; foliaceous dilatations yellow ; 9 yellow, mid-dorsal 

 line and incomplete transverse baud in middle black ; 10 black with 



