522. The American Naturalist. [June 
ZOOLOGY. 
Classification of the Nemertines.—There has been a disincli- 
nation on the part of some systematists to adopt the subdivisions— 
Palaeonemertini, Schizonemertini, Hoplonemertini and Malacobdellini 
proposed by Hubrecht. Dr. Otto Bürger has returned to the prob- 
lem, and he proposes‘ the following divisions : . 
Protonemertini in which the longitudinal nerve cord lies either in thé 
ectoderm or between this and the muscular layer; Mesonemertini in 
which the cords are in the muscular layer, and Metanemertini in which 
they are found in the body parenchyma. Bürger further calls atten- 
tion to “ lateral organs” in many species of Carinella. They consist of 
epithelial discs, sometimes projecting sometimes grooved, richly supplied 
with nerves, and, although sometimes containing glands, always free 
from pigment. He halfway expects that some Nemertine will be found 
in which the whole lateral line is made up of such sense organs. 
Ceratodus.—At last we are to have an adequate monograph of this 
most interesting form. Some years ago the Royal Society of London 
gave a grant to ascertain its history. An English naturalist was sent 
to Australia, where he obtained considerable material for an account of 
this and the Monotremes, but this material has been treated in a regu- 
lar dog-in-the-manger fashion. Some two or three years ago, aided by 
funds from the Ritter foundation, Dr. Richard Semon went to Aus- 
tralia with the same object in view, and the results are now beginning 
to appear.? From the first parts we learn that Ceratodus is confined to 
the middle portions of the Burnett and Mary rivers; that it cannot g0 
upon land, and that it may be caught with a hook baited with almost 
any animal substance. The native name is given as Djelleh (we had 
supposed it to be Barramunda). It breathes between 30 and 40 times 
a minute. The reproductive season lasts from April to the last of No- 
vember, and is at its height in September and October. The eggs are 
enveloped in a gelatinous envelope, and their specific gravity is greater 
than that of water. The segmentation is much like that of Petromyzon 
and the Amphibia. The development within the egg occupies 10to12 
days, and the anterior extremities appear 14 days after hatching, the 
hinder after 2} months. No fold was observed connecting the anterior 
‘Verh. Deutsch. Zoolog. Gesellsch. III Jahresversammlung, 1894, p. 24. 
*Deuksch. Med. Nat. Ges. Jena. Bd. iv, 1894, also separate. 
