ELIOT: NUDIBRANCHS FROM THE INDO-PACIFIC. 247 



containing about loo teeth on each side of the rhachis. They are 

 bifid, bearing one, often not very large denticle below the strongly 

 hooked cusp. The innermost teeth are rather irregular, being some- 

 times simply bifid, and sometimes bearing one or even two denticles 

 on the inner side. The outermost teeth are low and bear three or 

 four serrulations on the broad apex. 



This specimen comes very near to the typical Chr. semperi as des- 

 cribed by Bergh. The only difference of importance is that it bears 

 lines which are frequently broken up into spots, whereas the typical 

 form has no lines but spots only. 



Chr. semperi var. nigrostriata. 



Four specimens from Maskat. The notes on the living animal say 

 the body was pellucid blue with deep purple diagonal streaks and 

 yellow spots. The branchiae pellucid yellow with a red alignment. 



The largest preserved specimen is 35 mm. long, 11 mm. broad, and 

 15 mm. high, being thus high and fairly stout in build. In all the 

 specimens the tail projects and, as preserved, is turned up. The 

 ground colour varies in the different specimens from slatey-blue to 

 grey, and bears two sets of markings, (i) A pattern of lines varying 

 from deep purplish black to slate colour. In one specimen the lines 

 are much as described by me (loc. cit.) in specimens from Zanzibar, 

 rather stiff and looking as if they were deeply engraved. In two they 

 are thin, but rather more freely drawn, more curved, and with 

 numerous branches. In the fourth they are not numerous, but much 

 broader than in the ordinary specimens, being bands rather than 

 lines. (2) Yellow spots which show traces of having been of a 

 peculiarly vivid colour. They are not blotches, but roundish spots, 

 the largest not more than 2 mm. in diameter, and most much smaller. 

 They are arranged fairly symmetrically in the interstices of the dark 

 lines, and form a more or less regular border round the mantle and 

 the foot. The pockets of the rhinophores and branchiiie are slightly 

 raised. The rhinophores are long, deeply perfoliate, grey (probably 

 representing red). The branchise are longish, eight in number, 

 simply pinnate, grey with remains of vivid yellow pigment inside, 

 but no black lines. The mantle is moderately ample over the head. 

 The foot narrow, expanded markedly in front, with a deep grove 

 and tentacular angles, which are as much as 4 mm. long. 



The buccal mass is rather large, and the salivary glands 12 mm. 

 long and 2 mm. broad. The radula and labial armature are as des- 

 cribed above for Chr. semperi, but the innermost teeth appear to have 

 regularly a single denticle on the inside. 



I think that the differences between these specimens and the 

 specimen first described are not sufficient to constitute more than a 



