Dr. W.C. M‘Intosh on the Boring of certain Annelids. 293. 
cessful in finding acid traces in the southern examples. For 
a considerable time I have been familiar with an acid reaction 
in the cutaneous textures of many Nemerteans, such as Bor- 
lasia olivacea, B. octoculata, B. lactea, Lineus longissimus, 
Stylus purpureus, Cephalothrix filiformis, Ommatoplea alba, 
O. melanocephala, O. gracilis, &c.; indeed acidity seems 
characteristic of the group, the only exceptions as yet observed 
being in the deeply tinted O. purpurea and in O. pulchra, 
which have an alkaline reaction, rendering red litmus-paper 
blue. One of the most vivid red streaks is caused by the 
common Cephalothrix filiformis, referred to above. Some 
species of Chone, again, which do not bore, likewise give 
an acid stain to litmus-paper. The mere presence of acidity, 
therefore, is no proof whatever that an animal bores. None 
of the Nemerteans, for instance, do so, their habitats being in 
muddy sand under stones between tide-marks, in fissures of 
rocks, or in the cavities of old shells and stones from deep 
water. It is well to bear in mind also that Dodecacerta con- 
charum and Stpunculus, both very common borers, show no 
acid reaction when tested with litmus-paper. 
While thus shutting out the chemical means of boring 
from being the law to be applied universally to the perfora- 
tions made by Annelids, I should deem it rash at present, on 
my part, to promulgate any new theory, or to support any of 
the old. 
Mr. Lankester concludes his paper with some remarks on 
“the specific title and distinction of the lithodomous Leuco- 
dore.” ‘'The boring species,” he says, ‘ does not differ ob- 
viously from Leucodore ciliata. I have not been able to 
make a comparison of specimens ; but it seems probable they 
differ only in habit.” Yet he suggests the name of ZL. cal- 
carea for the boring form. I cannot agree with the author here 
either ; for I have never seen more than a single British species 
of Leucodore, which, however, bores in materials very varied 
in their composition. It is unsafe to suspect a form to vary 
specifically simply on the ground of its habitat ; and assuredly 
some more weight would have been given to his view of this 
matter if he had founded the distinction on the abnormality of 
the hooks of the fifth segment of the body, or on the absence 
of the spear-tipped bristles which accompany them. The 
perusal of the remarks of M. de Quatrefages* on the dif- 
ferent species of Leucodore is somewhat unsatisfactory ; and it 
appears to me to be by no means certain that at least five of 
his species do not refer to one, or at most to two forms. It is 
further worthy of note that, so far as I am aware, no other 
observer (excluding the more than doubtful cases of M. 
* Hist. Nat. des Annelés, vol. ii. p. 296 ef seg. 
