Dr. W. C. M‘Intosh on the Boring of certain Annelids. 279 
race in all parts of the world ; for the Abbé Dicquemare long ago 
noticed this on the coast of France, and in more recent times 
M. Schmarda* describes and figures a species (Leucodore so- 
cialis) having a similar habit, on the coast of Chili, Mr. Alex. 
Agassiz another on the shores of the United States, M. de 
Quatrefages at Boulogne, M. Claparéde at Skye, and Dr. 8. 
Wright in the Frith of Forth. Mr. Lankester, however, does 
not allude to this habit; and such tubes are certainly rare on 
the calcareous rocks. Very short ones are occasionally ob- 
served on the surface of Corallina. These tubes are composed, 
according to the nature of the site, of minute grains of sand 
and mud, or pure sand, cemented together by a tough secre- 
tion, which likewise gives a smooth coating to their interior. 
They project sometimes nearly half an inch from the stone or 
other material; and, when laid along the surface, in some cases 
they exceed this in length. If the animals are scattered, it 
will readily be observed that each is supplied with two inde- 
pendent and occasionally divergent tubes, which thus corre- 
spond to the double nature of their perforations in the stone. 
Both are formed in the same way, the Annelid reversing itself 
in its gallery at will and augmenting the length of the quies- 
cent tube: thus the restless tentacles are observed to project 
now from the one and now from the other. The animal dis- 
plays great energy in proceeding with its work, its tentacles 
resembling a struggling Ascaris that has been seized by the 
middle and is endeavouring to make its escape. Not only are 
these organs thrown about in all directions, but each under- 
goes a series of vermiform wrigglings, no head meanwhile 
being visible from the aperture of the tube. After lashing 
the water for some time, they may be noticed moving along 
the surface of the stone with a serpentine motion like indepen- 
dent worms, and seizing any convenient particle of mud, sand, 
or food they may encounter. Upon effecting this, the tentacle 
is not contracted as in the Hydrozoa and Actinozoa, but its 
vermiform motions along the rocky surface remain unaltered, 
while the particle is observed to wend its way towards the 
mouth of the tube along the tentacle in a remarkable manner, 
to be seized by the lips of the animal. Bastert distinctly no- 
ticed this quality in the tentacles of Leucodore, mentioning 
that, however unwilling, the prey was dragged by the organs 
into the tube and consumed at leisure. Hence he inferred they 
had many of the properties pertaining to the tentacles of polypes. 
The fact also did not escape the notice of that most patient and 
keen observer of nature, Sir J. Dalyell, in “ Spo seticornis;” for 
he says, ‘ The particles that may be selected for the edifices are 
* Neue wirb. Thiere, 1. ii. p. 64, tab. 26. figs, 209 & 209 a, 
+ Basteri Opuscula Subseciva, tom. ii. lib. 3. p. 155, 
