1904.] FROM EAST AFEICA AND ZANZIBAR. 103 



One specimen from the East Coast of Zanzibar. Notes on 

 living animal : " Rhinophore bearers very large indeed ; colour 

 whitish, netted with orange." 



The alcoholic specimen is more stoutly built than those already 

 described. It is somewhat bent, and would be at least 30 milli- 

 metres long if stretched out. It is 5 mm. high and 4-5 broad. 

 The rhinophore-sheaths are 8 mm. high, the cerata 5-5. 



The tentacular process consists of 11 fairly long digits,^ all 

 distinct and none of them merely tubercles. The large rhino- 

 phores bear 7 digits, three in front quite separate, and five behind 

 united at the base. Posteriorly there are traces of what may be 

 a crest. Behind the rhinophore-sheaths are three pairs of cerata, 

 somewhat resembling those of Doto in general appearance. They 

 all bear three digits, above which rises the top, covered with knobs. 

 They also all bear three stout branchise, two of which are visible 

 from the outer side and are protected by the digits. 



The jaws and labial armature are much as usual ; the former 

 have blunt indentations on the edge. The radula consists of 27 

 rows with a maximum formula of 16.1.16. In the median tooth 

 the central cusp is rather longer than depicted by Bergh, and 

 there are 10-12 denticles and ridges on each side. The second 

 stomach and the praeputium are armed with black spines as 

 described by Bergh (Chall. Rep. I. c). The Hver sends branches 

 into all the cerata except the right-hand member of the fii"st pair, 

 but not into the rhinophore-sheaths. 



I am somewhat doubtful if this is really Bergh's B. exce2}ta : 

 there are diffei-ences in the arrangement of the cerata and branchiae 

 and the rhinophore-sheaths are relatively much larger. On the 

 other hand, the two specimens examined by Bergh did not agree 

 in details, and the present animal possesses more or less the 

 characters common to them. 



BoRNELLA SIMPLEX, sp. n. (Plate TV. fig. 5 c.) 



One specimen from Chuaka, East Coast of Zanzibar. The 

 following are the notes on the living animal : — " Very like j5. digi- 

 tata, but a distinct species. Anterior tentacles short and simple. 

 Whole coloration transparent, so that the walls of the heart 

 are distinctly visible. No opaque white or orange rings on 

 tips of cerata, but an orange network on the back and a row of 

 opaque white dots on the sides. Eyes not visible. Length 12 

 millimetres." 



Superficially the alcoholic specimen looks much like B. excepta 

 as described above and has the same Boto-like cerata, but it is at 

 once distinguished by having on each side of the mouth not the 

 usual tentacular rosette, but a single simple tubercle. The left 

 tubercle is larger than the right. The rhinophore-sheaths bear 

 six short digitations and a larger rounded knob behind. There 

 are four pairs of cerata, of which the hindmost are simple warts. 

 The others are similarly constructed, though the third pair are 

 smaller than the first two. Each is divided into four knob-like 



