216 Address delivered at the sixth and last 
Zoological Society. Some numbers of the splendid work on 
the Fishes of Ceylon, by Mr. J. W. Bennett, the commence- 
ment of which was announced at our last anniversary, have 
also appeared within the past year. 
At home our ichthyologists have not been idle. Our secre- 
tary has favoured us with some notes on the West Indian 
fishes, to which I have already called your attention, as hav- 
ing been sent to this country, and commented on, by Dr. 
Bancroft. It is needless to add, that he has contributed much 
to the determination of the species, and the general interest of 
the subject. Mr. Bennett is also at this moment busily em- 
ployed in arranging the ichthyological department of the 
museum of the Zoological Society; and has already charac- 
terised that part of it which includes the Sumatran collec- 
tion, in a catalogue which will appear in the forthcoming 
Memoirs of Sir Stam yford Rajffies. Myr. Yarrell, also, whose 
exertions in ichthyology have been so frequently brought 
before you by my predecessors in this chair, besides adding 
to our knowledge within the past year respecting several 
species of the British fishes, has enr iched our Fauna by two 
species hitherto unknown to it, the Sdlea pegtsa of Lacepede, 
and Céttus Bubalis of Euphrasen, 
I now beg to direct your attention in turn to the Inyerte- 
brated Animals. But on looking to the list of the late works 
on this subject, which it has been my duty to prepare to lay 
before you this day, and feeling how long I have already tres- 
passed upon your time and your patience, I must pass over 
these subjects more rapidly than I feel to be consistent with 
the merits of the authors or their works. 
The most important communication which has appeared, 
during last year, on the Mollisca, is the joint production of 
our colleagues Mr. Broderip and Mr. Sowerby, on some 
subjects collected by Captain Belcher, during the late expe- 
dition under Captain Beechey to the north-west coast of 
America. Sixty new species have been described by these 
gentlemen in the fourth volume of the Zoological Journal ; and 
nine species, chiefly from the same collection, have been sub- 
sequently added in the succeeding volume. Among these, 
two striking modifications of form have been characterised : 
one, belonging to the family of Turbinidee, under the name 
of Trichétropis ; ; the second in the group of Tunicata, under 
that of CheliosOma. 
Irom the accurate pen of the former of these gentlemen, 
our native Fauna has received the addition of two new species 
of Biaccinum, the B. acuminatum and fusiforme; the former 
from the coast of Devonshire, the latter from the south coast 
