The OpistJiohranchmia of South Africa. 91 



strong, somewhat compressed, the upper margin with several slight 

 transverse furrows. Close to the crest the (scarcely retractile) not 

 short-stalked rhinophoria ; the club rather slender, with about 18-20 

 rather stout lamellae and a rounded end papilla (fig. 7). The even 

 back somewhat convex ; the margin not very prominent, 1-3 mm. 

 broad, densely set with perhaps 3-4 indistinct series of rather small 

 papillae ; this margin in front reaching beyond the rhinophoria, only 

 interrupted in the middle of the anterior and the hinder end of the 

 back. The papillge (ejnnotidia) as in other Janidae placed without 

 order, small ; the outer quite small, the inner somewhat larger ; here 

 and there a solitary papilla was seen in the neighbourhood of the 

 margin. The papillae seemed nearly all present, and there was no 

 trace of dropped larger ones. The papillae of usual form, sometimes 

 a little nodular (fig. 6). Quite posteriorly on the back, 3 mm. from 

 its end, and submedian, still nearer to the right margin, the anal 

 papilla, directed forwards, gaping, with strong folds (fig. 8), at its 

 base behind a fine renal pore. The sides rather high, the genital 

 papilla with two openings. The foot scarcely narrower than the 

 back, the margin prominent, the tail short. 



The central nervous system yellowish, nearly as in the Janolus 

 australis, the large pedal ganglion lying on the outside of the 

 cerebro-pleural. 



The narrow lip disc with strong cuticle. The (fig. 11) huge bulhus 

 pharyngeus IVb mm. long by a breadth and a height of 7 mm., in 

 shape as in other -Janidae, the blackish anterior end of the mandibles 

 projecting in the inner mouth ; its sides are quite covered by the 

 mandibles; on the somewhat concave upper and on the convex 

 under side the strong (faintly reddish) yellowish transverse muscles, 

 the hinder end formed by the lingual musculature. The mandibles 

 (figs. 9-16) very powerful, their thickness in front and in the middle 

 3 mm. ; the colour of the thicker parts mahogany brown, in the 

 fore end and in the hinge blackish, the thinner parts reddish yellow ; 

 their length and their height equals that of the bulbus. They consist 

 of a little shorter but stronger anterior part, flattened in the fore end, 

 and a longer slightly quadrangular posterior. The anterior convex 

 part has on the outside (figs. 10, 13) a deep somewhat curved 

 perpendicular furrow for muscular insertion ; before this the mandible 

 is thicker, more convex, behind the furrow the part is more flattened. 

 The longer posterior part is by a deep longitudinal furrow and border 

 (also for muscular insertion) divided in two lips, a thinner superior 

 and thicker inferior, somewhat concave beneath. The inside of the 

 mandible shows (figs. 9, 11) the anterior part convex, prominent, 

 before passing into the smaller foremost part of the outside, above 



