Dr. W. C. Mcintosh 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 oUvaceaj B. octoculataj B. lactea^ Linens longissimus^ 

 Stylus purpureus^ Cephalothrix filiformis^ Ommatoplea albaj 

 0. inelanocephala, 0. gracilis, &c. j indeed acidity seems 

 characteristic of the group, the only exceptions as yet observed 

 being in the deeply tinted 0, purpurea and in 0. pulchra, 

 which have an alkaline reaction, rendering red litmus-paper 

 blue. One of the most vivid red streaks is caused by the 

 common CepJialotJirix filiformis, referred to above. Some 

 species of Ghone^ 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 Dodecaceria con- 

 charum and Sipunculus, 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, oi: to support any of 

 the old. 



Mr. Lankester concludes his paper with some remarks on 

 ^' the specific title and distinction of the lithodomous Leuco- 

 dorer ^' The boring species," he says, " does not differ ob- 

 viously from Leucddore 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 L. 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 Anneles, vol. ii. p. 296 et seq. 



