18 



SIR CHARLES ELIOT 



Tritonia, appendiculata, sp. n. 



One specimen marked " 9 Fathoms. April 1903. Harbour S Orkneys." (Station 

 325. Scotia Bay.) 



The animal has the usual shape of Tritonia : on the left side is a large blister, prob- 

 ably accidental. The length is 51 "5 mm., the maximum height and breadth 12 and 16 

 respectively. The colour is a uniform dirty greenish-yellow. The back is thickly 

 covered with small round flat warts. The oral veil is 127 mm. wide. It does not 

 project much from the head, and bears twelve simple digitate processes, most of which 

 are about 2 mm. long, but two are very small tubercles. At the ends of the veil and 

 below the outermost process on each side is a large grooved tentacle, of the shape usual 

 in the genus. The lips project on each side of the mouth as distinct ridges, prolonged 

 at the top into free cylindrical processes 2'5 mm. long, resembling tentacles. 



FIG. 6. Branchia. 



FIG. 7. Portion of eilgt- ol jaw. 



FIGS. 6 to S. Triton in appeudiculata . 



FIG. 8. Median tooth. 



The sheaths of the rhinophores are 3 mm. high and 3 '5 mm. broad ; the margins are 

 jagged. The rhinophores are thick clubs, surrounded by about ten simply pinnate or 

 bipinnate plumes, white, with greenish tips, and hard to separate from one another. 

 The dorsal margin is distinct, 3 mm. broad, and starts from the back of the rhinophore 

 sheaths, to which it is attached, giving them a somewhat elongated appearance 

 behind. 



On each side are nineteen branchiae (fig. 6) of various sizes, but those on the left are, 

 on the whole, rather larger than those on the right. They are scanty, and not foliaceous. 

 The smaller are simply bifid ; the larger consist of three processes set on a common 

 prominence ; each process is twice bifurcate. The anus is 22 and the genital orifice 

 15 mm. from the anterior end of the body. The former is just under the dorsal 

 margin, the latter half-way up the side of the body and surrounded with ample folds. 



There is no tail separate from the body. The foot is rounded and grooved in front, 

 where it is thickened by a layer of what appear to be glands. 



The pericardium and heart are as usual. The central nervous system is large, but 

 no eyes were found. The ganglia are yellow and smooth, showing no signs of granula- 



(ROY. soc. EDIN. TKANS., VOL. XLI., 526.) 



