34 Marine Investigations in South Africa. Vol. V. 



about 20 lamellae on each side of the smooth rhachis. No caudal 

 finger. 



The inside of the mouth tube black. The whitish bulbus 

 pharyngeus 7 mm. long by a breadth of 6 and a height of 5 ; 

 the pharynx black, as also were the walls of the mouth-cavity. 

 The mandibles under the black coating wax-white ; their somewhat 

 compressed elements of the usual form (figs. 12, 13) 0-20 mm. high, 

 their upper facet of a length of 0-06. The rasp of the tongue, dirty- 

 brown, seemed to contain about 22 rows of plates, in the sheath 17, 

 the total number of rows being thus 39 ; in the series on each side 

 of the narrow rhachis very likely about 60 plates. The basal part 

 of the plates reddish brown, their height reaching to about 04 mm., 

 that of the two outermost 0'14 and 0-16; their form (figs. 14, 15) the 

 usual, the outermost mostly without the denticle. 



The whitish, roundish, flattened gl. salivalis of 5 mm. diameter; the 

 gl. ptyalina very developed. 



The brownish gray liver 13 mm. long by a height of 7. The large 

 whitish kidney 12 mm. long by a height of 7 and a thickness of 2, 

 with many transverse furrows. 



The yellowish hermaphrodite gland lying on the hinder end of the 

 liver and the kidney, and continued along the upper margin of 

 the latter ; in the male and female lobules ripe genital elements. 

 The anterior genital mass somewhat compressed, 10 mm. long, 

 and, as far as could be determined, as in the typical species. 



OSCANIOPSIS, Bgh. 



E. Bergh, Die Pleurobranchiden, 1, 1897, p. 53. (Malacolog. 



Unters. V., p. 53 (-61).) 

 Vayssiere, Monogr. de la Fam. des Pleurobranchid6s, h. Ann. 



des sc. nat. Zool., 8 S., xii., 1901, pp. 6-15. 

 R. Bergh, Die Opisthobranchiata der Siboga Exped., 1905, 



pp. 49-52. 



Caput discretum nullum. Notaeum a velo (scuto) frontali 

 (tentaculari) latissimo non discretum, applanatum, laeve, testa 

 nulla; tentacula sicut rhinophoria distantia, lateralia, canaliculata. 

 Rhachis branchiae serie nodulorum duplici instructa. Apertura 

 genitalis simplex. Podarium magnum, infra massa glandulari 

 caudali mediana prseditum. 



Connectiva cerebro- et pleuro-pedalia brevia sed distincta. — 

 Mandibulse ex elementis applanatis compositge. 



This group represents a passage from the Pleurobranchseae to the 



