566 PKOF. C. H. O^DONOGHUK : KEPOBT ON 
the valves, particularly the lateral ones, possess on their margins curious 
spatulato processes, which were described and figured by Eliot. The valves 
are very hard and bend over almost to touch the dorsum, so that the tiny 
gill-plumes, apparently arranged in three groups, cannot be seen without 
cutting off the valves. 
Labial Armature. According to Eliot there is no labial armature, but in the 
specimens here described a circular ring of chitinous cuticle was present. 
It is not large and quite thin, but, nevertheless, it resisted boiling in potash 
solution and separated off from the lips as a distinct ring. 
Radula. The radula contains no rachidial teeth. It is only moderately 
developed, and contains from 56-58 rows. The tirst row contained 18 . . 18 
a. e., 36 teeth), and the middle rows (34-42) . . (34-42), i. e. (68-84). The 
teeth are erect, moderately long, and slender, and so closely packed at the 
outside that they are difiicult to count accurately. They are a little larger 
on the outside, but otherwise very similar throughout. Each consists of a 
more or less rectangular blade-like plate, one corner of which is carried on 
as a thin, slightly curved rod, bearing at its tip a small rounded secondary 
denticle. They are similar in general appearance, although differing in 
detail from those described by Bergh for N. citrina (11). 
Notes. Three specimens were represented in the collection, and bore the 
label " 1st Island. Shore Collecting. Outer side." 
Professor Dakin, in his general account of the Abrolhos, says of this 
species: — "A straggling brilliant lemon-yellow sponge was one very evident 
specimen. After turning several stones over and noticing what appeared to 
be pieces of this sponge falling off, it was discovered that the falling pieces 
were Nudibranchs resembling the sponge both in colour and general a])pear- 
ance. The species belongs to the genus Notodoris, this being the first record 
for the genus on the Australian coast. It was instituted by Bergh for a 
single specimen of N. citrina from Rarotonga. Two other species have been 
made by Eliot for specimens from Zanzibar and the Maldive Islands. All 
three are yellow in colour. It is stated in Eliot's report that nothing is 
known of the habits of these animals, and further : — ' With Mr. Gardiner's 
specimen is a piece of hard yellow sponge. There is no note, but as the 
colour and consistency of the sponge closely resemble those of theNudibranch 
it is highly probable that the latter frequent it.' 
" It is interesting to find that this is actually the case and in an eutirel}^ 
different region. Our specimens were always found associated with this 
sponge. The Nudibranch moves about slowly, so far as could be observed, 
and apparently lives in the dark under coral blocks." 
This association between Nudibranch and sponge is not unknown, as 
witness the entirely different brilliant v^'A^wAibvimch Rostanga pulcliralb/'mg 
on a similarly coloured sponge on the Pacific coast of North America {;vide 
O'Donoghue, 60, p. 152). 
