140 MESSRS. ALDER AND HANCOCK ON 
The liver is, in a great measure, retained within the visceral cavity, as an elongated, 
folliculated mass, the anterior extremity of which, extending up the left side of the sto- 
mach, is attached to that viscus, and opens into it a little behind the cesophagus. Fol- 
liculated branches pass from this biliary organ to the branchial tufts, and penetrate to 
the papillz, within which they terminate in slightly branched or folliculated prolonga- 
tions. The anterior pair of tufts, however, receive their branches from folliculated 
masses attached to the dorsal wall of the stomach in front, which masses open into the 
anterior portion of the stomach. 
The reproductive organs, as far as they could be determined, resemble those of Den- 
dronotus ; and, as in it, the ovary lies above the liver or central folliculated trunk of 
the gastro-hepatic system. 
The vascular system is also similar to that of Dendronotus. ‘The heart occupies a 
distinct pericardium, on opening which it is easy to see that the blood is returned from 
the branchiz by four lateral vessels, two in front and two behind. The gills are very 
peculiar : they are in the form of pedunculated tufts, each tuft being composed of simple 
papillee and laminated plumes ; and it is evident that the blood takes a definite course 
through both structures. It finds its way through the cellular tissue of the peduncle 
into all the divisions of the tufts ; it then passes over the aérating surfaces, and reaches 
the efferent branchial channels which run down the outer margins of the papillae and 
plumes, and unite at the base to form one common trunk, which descends at the posterior 
margin of the peduncle. Arrived at this point, the blood falls into the great lateral 
channels that lead to the auricle. From these facts there can be little doubt that the 
papille, as well as the plumes, are gills, only the latter are a little more differentiated 
or somewhat more highly organized. That the one is only the other modified, we have 
a proof in an abnormally developed plume which one of the specimens exhibited: this 
plume retained to a considerable extent the appearance of a papilla. 
The cerebral ganglions are arranged as in Dendronotus. The cerebroid and branchial 
are fused into two oblong masses, which are united across the median line ; and the pedal 
lie beneath the cesophagus : the commissural cord has disappeared, these latter ganglions 
being united by their inner margins below the cesophagus. 
Bornewia pieirata, Adams. (Pl. XXXIII. figs. 8, 9.) 
Body nearly linear, rounded above, flesh-coloured, covered with crimson reticulated 
lines. Sides of the head produced in front into two star-like, rounded lobes, with six or 
seven radiating filaments on the margin and others beneath. Tentacles clavate or fusi- 
form, obliquely laminated, retractile within long cylindrical sheaths, the upper margin 
of which bears four linear papillz, one of which is much larger than the rest and clavate, 
banded near the top with crimson, and tipped with yellow. Branchial processes six on 
each side of the back, in single series, diminishing posteriorly: they are pedunculated, 
branching above into two or three stout papille, each with a band of crimson, above 
