Mr. C. Spence Bate on Crustacea. Ttz 
the birth of the larva. (2) The most certain mark by which a 
young animal may be known is the immature condition of the 
antenne, more especially the flagella; now, whilst in the larva 
of the Palinurus they are very rudimentary, in Phyllosoma they 
assume an adult character, and in the second pair one that is 
of a peculiar feature, at least in the species to which we refer. 
(3) The oral appendages appear to be present, though only 
as the germs of the future parts; whilst in Phyllosoma they 
appear to exist in a rudimentary condition that assimilates 
little to a progressive stage. (4) Double branchial vesicles are 
attached to the coxe of each pair of pereiopoda, whilst none 
exist in the larva of Palinurus. We must admit, however, 
that this argument is not very strong, seeing that in the adult 
Palinurus such organs are present, and that there must be a 
period when they first appear; and it ts most probable that 
their earliest stage is of the most simple character. And per- 
haps we should not have thought it sufficiently important to 
have remarked upon, had not M.Gerbe stated that Phyllosoma, 
like the larva of Palinurus, was without branchial appendages, 
and M.M.-Edwards remarked that these vesicular appendages 
are vestiges of the external branch of the limbs. (5) Phyllo- 
soma is a tropical genus, and with such we can only compare 
the larva of Palinurus ; two specimens only of the former have 
been obtained in the British seas, whereas Palinurus is very 
common on our coasts—an argument that might be very forc1- 
ble were we not cognizant of the fact that we are quite as much, 
if not more, in the dark in relation to the development of the 
common lobster. 
Our ignorance upon these interesting and important points 
in the history of the Crustacea, together with the discovery of 
Fritz Miller that the larva of Peneus, and probably that of 
some other prawns, very closely resembles that of the cirripeds 
and other entomostracous larvee, shows that there is much yet 
to be done of far more interest to zoological science than the 
mere discovery of new species to be added to our fauna. The 
great diversity of structure, and the wonderful variation in the 
development of animals that possess a great similarity in their 
adult condition, indicates that careful study of these animals 
will probably assist in throwing a considerable hght on some 
of the more profound problems of biological knowledge. 
Several specimens of Scyllarus arctus have been taken recently 
on our coasts. It is some years since Mr. Couch announced 
the first appearance of this as a British species ; and none has 
since been recorded until these last two years, when six have 
been taken near Penzance by Mr. Cornish, and one off the 
Mewstone, near the eastern entrance of Plymouth Sound ; two 
