220 
to a phase considerably in advance of the well-known locomo- 
tive gemmules of the marine bryozoa. 
Dr. Allman also made some observations on the Anatomy 
of Polycera quadrilineata. 
In this mollusk the buccal mass is furnished with two pow- 
erful corneous jaws, acted on by distinct muscles, and con- 
tains a spinous tongue of very complex structure. The ceso- 
phagus leads to a stomach, which is imbedded in the anterior 
extremity of the liver, and from which an intestine first passes 
forward and then curves backwards, to terminate at the anal 
outlet, which is situated between the two posterior leaflets of 
the bronchial tuft. Two pair of glands are connected with 
the buccal mass. The liver, though in its natural condition 
it is compact, like that of Doris and its allies, may yet be 
unravelled so as to display its minute structure ; and it is then 
seen to consist essentially of a ramified tube, whose branches 
end in slightly dilated culs de sac, and are furnished along 
their sides with closely-set spheroidal divertacula, which 
would seem to be the essential secreting portion of the organ. 
The heart consists of an auricle and ventricle, and occu- 
pies the back of the animal immediately in front of the bran- 
chial tuft; it is furnished with auriculo-ventricular and aortic 
valves. 
The brain consists of six supra-cesophageal ganglia, and 
the nervous collar is completed below by a band of nervous 
matter, which passes from the most external ganglion of one 
side, round the ventral aspect of the cesophagus, to the corres- 
ponding ganglion of the other side; the nerves which supply 
the dorsal laminated tentacula are furnished at their base with 
large ganglionic dilations; and two small pharyngeal ganglia 
are placed upon the ventral aspect of the cesophagus just as 
this tube leaves the buccal mass, 
The eyes are almost sessile upon the anterior ganglia of 
