TRANSACTIONS OF SECTION D. 545 
interesting species, long a puzzle to naturalists, the author afterwards found in 
some abundance, and was able to study at leisure. It is a slender white worm, 
_ having a peculiar cordate leaf-like snout, from the base of which arise two long 
tentacles studded with rows of conical papille. The mobile snout enables it to 
burrow rapidly through the sand, and when at rest it assumes an erect position 
below the surface, the long branchize waving about in the water. It does not 
build any tube. Altogether he collected about sixty species during his stay at 
Southport. 
As early as 1745, Bonnet proved that the Nais and other worms, after division 
into various parts, after a time regained the power of feeding and reproducing new 
segments. The slight adhesion between one part and another, and the readiness 
with which species break up into fragments, is often a source of embarrassment to 
the collector. Thus, however carefully handled, he was never able to obtain an 
entire specimen of a very beautiful Polynoe (P. asterine) which occupied the 
ambulacral grooves of Asterinas aurantiaca. 
The species of Nemertes, again, without apparent cause, undergo spontaneous 
sloughing or deliquescence. Many other Annelids, when kept on short commons, 
undergo a process of budding or fission. This phenomenon can be well studied in 
Nais proboscidea, the new formation taking place in front of the terminal segment. 
Sometimes as many as four or six individuals are thus interposed between the head 
and tail of the original worm. In Scyllis and other genera the budding has a 
sexual import, the detached individuals forming, in fact, locomotive ovarta. The 
production of egg-bearing somites is exhibited on a large scale in such entozoa as 
the Tape-worms. Dr. Williams, in his Report on Annelids (British Association, 
1851), denies the whole of what Bonnet and others have recorded respecting the 
reproduction of lost parts in Annelids, although he admits a process of gradual 
sloughing from injury or starvation ; but the phenomena have been noted too fre-~ 
quently by independent students to leave any doubt respecting them. It would 
be out of place to enter into any structural details. In all Annelides the division 
into segments (of which the common worm is a typical example) prevails—only, 
instead of the simple bead-like structure, new organs are superadded, so as to fit 
the species for progression in the pursuit of prey (Errantia), or for swimming 
(Phyllodoce), or burrowing in the sand. 
In the sedentary species the anterior portion is still further modified by the 
addition of tentacule, so as to enable the individual to search for food or materials for 
constructing its tube: or designed for the protection of delicate parts (such as the 
branchiz) from the encroachments of enemies. Examples of this kind may be 
found in the cork-like stopper of Serpula, which effectually closes the mouth of the 
tube. A similar protection from enemies is seen in the crescentic coronal of Her- 
mella, and the golden combs of Pectinaria. Lastly, the contrivances for the aéra- 
tion of the red fluid we may call the blood, are remarkably varied and beautiful. 
They advance from a simple ciliated process given off from each segment, through 
every grade of complexity, to the shrub-like ramifications of Arentcola. The 
colouring of the species is equally variable: white, flesh-tinted, ruby-red, sea-green, 
violet: the surface often glowing with pearly or metallic iridescence. When we 
remember that the Annelides, constituting the chief food of many fish, birds, and 
crustacea, are subject to the attacks of various enemies, and that their delicate 
bodies are liable to constant mutilation from the drifting of the sands and the 
action of the waves, we see the reason for the recuperative power they possess. 
The author mentioned a remarkable instance of survival under difficulties ex- 
hibited by a Terebella which was packed away among his books when he left 
Southport. The specimen was a mature worm with a portion of the tube, left in 
the bottle just as he collected it, with a little sea-water and sand. On opening the 
box four months afterwards, the creature was still living, although reduced to a 
mere stump. During the interval it had actually carried the tube, growing thinner 
and more transparent from lack of material, three times round the bottle. 
The higher order of Annelids, the Errantia, are represented only by those 
species which can bury themselves in the sand. In the absence of the shelter 
afforded by vegetation, by boulders or the holes and crevices on rocky shores, where 
1883. NN 
