NOTES ON NUDIBRANCHS. 
83 
The form is common in the Indo-Pacific, at any rate on the East 
African coast. It may be doubted whether the species of Hexa- 
branchus are for the most part more than colour varieties. 
Trippa, Bergh. 
The genera Trippa and Phlegmodoris were created by Bergh as 
separate in 1877 and 1878 respectively, but subsequently united 
(see Bergh in Semper’s Reisen Heft. XVII., p. 904; id. SibogaExp. 
Opisthob, p. 129). This amalgamation is undoubtedly correct, for 
though the two types T. ornata and Ph. mephitica are not much 
alike in appearance, they agree in their anatomy, and the external 
structure is fundamentally the same in both, as the back is soft but 
spiculous and covered with compound tubercles. In the internal 
organs there is no armature on the labial cuticle or genitalia ; the 
radula is rather small, and consists of hamate laterals without a 
central tooth ; and the only special feature is the presence of ptyaline 
glands at the extremity of the oral tube. It may be doubted if 
these glands should be considered a necessary character of the 
genus. 
I think that I have shown in the descriptions which follow that 
the two animals named above are identical with Doris intecta , 
Kelaart, and D. areolata, A. & H., and should therefore be called 
Trippa intecta and Trippa areolata respectively. T. monsoni from 
East Africa* (? = Doris leoparda, Kelaart) also seems to have the 
full characters of the genus, but is small and perhaps immature. 
The other species are more doubtful. T. affinis, B., is probably a 
variety of T. intecta, and T. spongiosa (Kel.) of T. areolata. Though 
the characters of T. ? hispida, B., and T. ? anceps, B., are clear, 
Bergh himself expresses some doubt whether the animals are really 
referable to Trippa. T. luteola (= Thordisa ? caudata, Farran) is 
perhaps referable to this genus, for it has flat tubercles bearing 
secondary spiculous projections, and also smooth patches among 
the tuber6les which perhaps correspond to the pits of other species. 
Also it has ptyaline glands. But it must be admitted that in 
general appearance it is not like the typical species. 
Trippa intecta (Kelaart). 
— T. ornata, Bergh. 
See Kelaart I., p. 302; Eliot I., p. 658; Bergh in Semper’s Reisen 
Heft. XII., p. 543; and Heft. XVII., p. 905 ; id. Siboga Expeditie, 
p.129-33. 
Nine specimens from Trincomalee. The largest is 55 mm. long 
and 37 broad, the smallest 18 mm. long and 12 broad. The colour 
varies from bottle green to black, with white markings, and the 
smaller specimens are the darkest. The white markings are absent 
* See Eliot, in Proc. Z. Soc., 1903, p. 371, and id. I., p. 660. 
