On a Whale-barnacle from Antarctic Seas. 1G5 



XX. — A Whale-barnacle of the Genus Xenobalanus from 

 Antarctic Seas. By W. T. CALMAN, D.Sc. 



(Published by permission of the Trustees of the British Museum.) 



AMONG the barnacles that infest the skin of whales Xeno- 

 balanus globici pit is, Steenstrup, is remarkable.in that, although 

 belonging to the sessile or operculate group of the Oirripedia, 

 it closely resembles in general appearance the species of the 

 ■ pedunculate genus Conchoderma. It has hitherto been known 

 only from the North Atlantic, and it seems desirable, there- 

 fore, to record the fact that the Natural History Museum has 

 recently received specimens of what appears to be the same 

 species from the Antarctic region. 



Xenobalanus globicipitis, Steenstrup. 



Xenobalanus globicipitis, Steenstrup, Overs. K. danske Vidensk. Selsk. 

 Fork. 1852, no. 2, p. 158 ; id. Vidensk. Medd. Nat. Foreu. Kjoben- 

 havn, 1851 (1852), p. 62, pi. iii.figs. 11-15 ; Darwin, Balanid;©, 1854, 

 p. 440, pi. xvii. figs. 4 a-i c ; (with var. pallidus) Pilsbrv, Bull. U.S. 

 Nat. Mus. xciii. 1916, p. 283, pi. lxv. figs. 2, 2«, 2 6. 



Locality.— South Shetland Islands, 5th March, 1918, from 

 the tail of a finner-wliale. Collected by Mr. A. G. Bennett. 



Distribution. — Faroe Islands, between Madeira and Eno- 

 land, Madeira, Azores (Steenstrup, Darwin) ; Ne\\ r England 

 (Pilsbry) : on pectoral, dorsal, and tail-fins of Globicephala. 

 Shetland, on tail of Balcenoptera physalus, R. C. Haldane 

 Coll. (Mus. Brit, and Mus. Zool. Cambridge). 



Remarks. — The specimens from the South Shetlands are in 

 very bad condition, few of them showing more than the basal 

 star-shaped shell and the empty cuticle of the body-sheath. 

 In one specimen two or three cirri are preserved. Further, 

 in consequence of having been kept for two years in 

 formalin, the shell is in all cases exceedingly friable, so that 

 it falls to pieces almost at a touch. In all characters that 

 can be ascertained, except that of size, however, the specimens 

 agree with the descriptions of X. globicipitis and with the 

 specimens in the Museum collection. Darwin states that the 

 largest specimen he had seen was nearly 2 inches long, and 

 that its shell measured " from extreme point to point nearly 

 a quarter of an inch in diameter." Among the specimens 

 from the South Shetlands the longest measures 75 mm., and 

 it is imperfect at the distal end, so that its length may have 



