1902. 



NUDIBRANCHS FKUM ZANZIBAR. 



Q5 



markings. Round the edges of tlie lobes, the angles of the body, 

 the ridge of the tail, the cups of the rhinophores, and the frontal 

 veil runs a brown line. The surface of the l>ody is covered with 

 microscopic bi-own specks, which here and thei'e are aggregated 

 into spots just visible to the naked eye. There are also a few 

 other spots. 



There are no anterior tentacles, but a small frontal vehun. 

 The rhinophores are perfoliate and set in little open cups on the 

 top of fairly long pillars, which ai-e usually held nearly hoi'izontally 

 and have not any process behind as in Soyllcea (see PI. V. fig. 5). 

 The back and inside of the wings are covered with colourless, 

 transparent contractile branchire similar to those of ScyUa'a 

 (text-fig. 3, p. 66). Oa the tail is a slight ridge, not amounting 

 to a crest. The foot is verv nai-row. 



Text-fi"-. 



Digestive organs of CrosslawJUx rii-iilis. 

 oc., cBsophagus. | gl., gland. | st.pl. , stomach-plates. 



The body-cavity is spacious anteriorly until the commence- 

 ment of the liver. After this point it is quite narrow, owing to 

 the thickness of the soft transparent body- wall. The jaws (PI. V. 

 figs. 7, 8) are large and hinged dorsally. The masticatory edge 

 is smooth and flexible, of a deep brown colour and bent outwards, 

 the muscles being attached at the bend and covering the large 

 stifi' cheeks. The radula (PL V. figs. 4, 6) is short ; each I'ow con- 

 sists of a median tooth and about 30 laterals on each side. The 

 median tooth has a fairly large spine in the centre of the anterior 

 margin and about 5 denticulations on each side, of which the 

 pair nearest the centre are considerably larger than the others. 

 The lateral teeth are also denticulate, but vary somewhat in form, 

 and the coi'responding teeth in the difterent I'ows do not always 

 Proc. Zool. Soc— 1902. Yol. II. No. Y. 5 



