1906.] OF SOUTIIEUN IXDIA AND CEYLON. G71 



1867." It appears to be specifically the same as the smallei' 

 specimens. 



It is rather rectangular in outline and measures 106 mm. in 

 length, 49 in breadth, and 41 in height. The coloration is brown 

 of various shades ; the dorsal sui'face and most of the branchiae 

 are dark brown ; the sides of the body, the foot, the exserted 

 proboscis, the rhinophores, all the dorsal processes and in places 

 the tips of the branchiee are light yellowish brown. 



The back is flat ; the margin does not project, but is clearly 

 marked by a line of ramose processes extending at least as far 

 back as the branchiae. Of these processes, eight on each side are 

 taller than the others, and the largest are about 6 mm. high and 

 5 mm. broad. They are branched three or four times, but as 

 preserved suggest not so much branches as aggregations of 

 tubercles. There are ten similar but rather smaller processes 

 on the oral veil, varying from 2 to 5 mm. in length. Besides 

 these marginal aj)pendages, both the back and the sides of the 

 body are ii-regularly spi'inkled with processes of all shapes and 

 sizes, varying from a height of 2 mm. to microscopic dimensions. 

 The larger are distinctly ramose, the smaller apparently simple. 



The rhinophore-pockets are not much raised and the margins 

 are studded with small processes like the rest of the back. The 

 rhinophores are completely retractile, smooth below, but bearing 

 about 40 perfoliations on the top part, which is bent backwards. 

 The large branchiae cover the posterior third of the back. 

 They are quadri- or even quinque-pinnate and consist of four 

 groups : — 



(a) Left posterior. An enormous plume, 30 mm. long and 



35 broad, arising from a single stem, but dividing close to 

 the base into two large and two smaller branches. There 

 is a pocket-like hollow round the base, but the plume is by 

 no means retractile and extends beyond the doi'sal margin, 



(b) In front of this large plume and a little nearer the median 



line is a smaller group (14 mm. x 16 mm.) with three main 

 divisions, (c) Rather to the right of this and on the 

 middle line of the back is another group of two plumes 

 (about 20 mm. x 12 mm.), which seem to rise from a 

 common base. 

 {d) On the right is another group, about the same size as the 

 la,st, which seems to consist of two plumes arising from a 

 common stalk, though it is hard to be certain of this as 

 the back is much corrugated. There is no large plume on 

 the right corresponding to (a), and the whole arrangement 

 of branchiae is asymmetrical. The anal papilla is on the 

 median line just to the right of [a). Though the opening 

 is very large, it is low and inconspicuous. In front of it 

 lies another opening, probably the renal pore. On the 

 right side of the body, about halfway down and 25 mm. 

 from the frontal veil, is the genital opening — a large simple 

 pit in the interior of which ai-e th-e separate sexual orifices. 

 Peog. Zool. Soc— 1906, No. XLV. 45 



