GENUS XENOBALANUS. 489 



Hab. — North Atlantic Ocean, attached to Porpoises ; Mus. R. T. Lowe, 

 Steenstrup. 



This Cirripede, in appearance the most anomalous of its 

 family, has affinities distinctly pronounced. Four years 

 ago the Rev. R. T. Lowe sent me some specimens, which 

 he had obtained from a porpoise between Madeira and 

 England; and I named them in MS. Siphonicella, from 

 their relationship to Tubicinella, — a fact which I mention 

 only because Sir C. Lyell has alluded to this genus under 

 the above name (without any description), in his anniversary 

 address to the Geological Society, as have I, in my 

 volume (p. 156) on the Lepadidse. Since that time Pro- 

 fessor Steenstrup has described and named the genus, fully 

 recognising its place and affinities, and has most kindly 

 sent me a magnificent group of specimens. 



This genus singularly resembles, in general appearance, 

 some of the pedunculated Cirripedes, so much so that in 

 the specimens sent me by Mr. Lowe, in which the almost 

 rudimentary shell was, from disintegration and its deep im- 

 bedment, not plainly visible, I did not in the least doubt 

 that I was examining a new genus of Lepadiclae. I may 

 mention, as a proof how truly all the parts and organs are 

 correlated in Cirripedes, that I was at first in despair when 

 I found a species to all appearance pedunculated, with its 

 labrum not bullate, its palpi of large size, its third pair of 

 cirri totally unlike the fourth and succeeding pairs, and with 

 only a single layer of muscles round the peduncle ; but when, 

 in addition, I found that there were branchiae, and that these 

 were double, I felt convinced that I was dissecting a dis- 

 guised sessile cirripede, and that its true place was near 

 Coronula : soon, I found the imbedded and almost rudi- 

 mentary shell, of which a mere fragment would equally well 

 have declared the true position and relationship of the whole 

 animal, Though Xenobalanus, in external aspect, is so com- 

 pletely masked, yet in its habits, namely, in living attached 

 on Cetaceans, as in its essential structure, it displays its 

 real affinities. In the course of the following description, it 

 will be seen that in the shell, the affinity is almost equally 

 close to Coronula and Platylepas, but that, considering the 



