286 Dr. W. C. Mcintosh on the Boring of certain Annelids. 



out the water with which the bottom of the tube may be filled ;" 

 and thus the Annelid '' amid the raging billows is securely 

 anchored to its cell." From the siphonal nature of the tube, 

 this description cannot apply in any degree. 



Another very common borer in shells, nullipore, and calca- 

 reous rock is Dodecaceria condiarum^ CErst., a Cirratulean 

 which has a larger tube, shaped something like a keyhole 

 in transverse section, and terminating in a slightly dilated, 

 smooth, csecal extremity. This animal likewise lives in the 

 fissures of the rocks in the Channel Islands, forming in the 

 mud long galleries bent in various ways, but always readily 

 distinguishable from those of Leucodore. In addition to the 

 foregoing localities, a specimen was sent me alive from St. 

 Andrews rocks in its characteristic tube in sandstone. In 

 this instance the perforation in the stone was lined by a con- 

 siderable coating of carbonate of lime, so that it had a smooth 

 whitish aspect — as if the animal had not relished constant con- 

 tact with the rough grains of sand, and had fashioned a coat- 

 ing analogous to the well-known secretion of Teredo. Even 

 in the spreading base of Gorallina officinalis^ the gallery in- 

 habited by this animal is often so smooth, and its appearance 

 on fracture so characteristic, that the observer is led to suspect 

 the existence of some secretion which covers over the rougli- 

 nesses of the tube and the rocky surface. The bristles (PI. XX. 

 fig. 4) in this species have a dilated and flattened tip with a 

 finely serrated edge, and taper to a fine point. The shape of 

 the hooks (figs. 2 & 3) is peculiar and characteristic, and en- 

 ables the observer to distinguish the dried remnants at once. 

 The animal tinges the spirit of a rich dark-green hue, just as 

 Sark specimens of its ally Cirratulus cirratus do, but gives 

 no acid reaction to test-paper. The Nereis sextentaculata of 

 Delle Chiaje*, which lives in holes in the rocks of the Nea- 

 politan shores, is, in all probability, referable to the same spe- 

 cies : and the Narganseta corallii of Leidy f is likewise either 

 the same or a very closely allied form. The latter bores dead 

 portions of Astrangea astrcsformis. 



A third British borer is Sabella saxicava, Quatref., whicli, 

 according to Messrs. Stewart and Lankester, is found in the 

 limestones near Plymouth ; and I have found it abundantly 

 in Oyster, Pecten^ Anomia^ and other dead and living shells 

 dredged off the Channel Islands, as well as perforating tlic 

 Balani that cover the sides of the Gouliot caves at Sark, near 



* Memoiie sulla Storia e Notomia degli Animali senza Vertebre del 

 Regno di Napoli, vol. iii. p. 176, tab. 43. fig. 16. 



t " IVLarine Invert, of Rhode Island and New Jersey," Joum. Acad. Nat. 

 Sc. Philad. ser. 2. vol. iii. 



