440 BALANlDiE. 



whole animal, the affinity is somewhat closer to Tubicinella. 

 Xenobalanus may indeed be described as a Tubicinella 

 without opercular valves, — with the opercular membrane 

 thickened down to the basis, — and with the shell, excepting 

 the few last-formed basal zones of growth, almost wholly 

 removed by the breakage of its upper end ; this remnant 

 of a shell, however, presenting some strong points of 

 resemblance to Coronula. 



Xenobalanus globicipitis. PI. 17, fig. 4> a — 4 c. 



Xenobalanus globicipitis. Steenstrup. Videnskabelige Meddelclser 



fra den Naturhist. Forcning i 

 Kjobenhavn, for Aaret, 1851. Tab. 

 3, fig-. 11—15. 



General Appearance. — The shell is in an almost rudimentary condi- 

 tion, and appears like a small white irregular star, imbedded up to its 

 top in the skin of the porpoise. Out of this thin, star-shaped shell, a 

 cylindrical, flexible, peduncle-formed body springs, which forms the 

 main part of the animal ; it is narrow where coming out of the central 

 cavity of the star, but soon acquires its full diameter; at the upper end 

 it has a reflexed hood, and hence is broader, and this has the appear- 

 ance of forming a capitnlum, like that of a pedunculated Cirripede. 

 This pseudo-capitulum is formed by a membranous reflexed collar or 

 hood, which is very narrow at the lower end of the orifice, close under 

 the mouth, and becomes wider and wider towards the upper and 

 carinal or posterior end of the orifice ; hence the lower reflexed edge 

 of the hood is only slightly oblique or even nearly transverse. The 

 orifice leading into the sack is large, and nearly in the same straight 

 line with the peduncle ; it is a little hollowed out in the middle at the 

 upper end, and on each side of this medial hollow, there is a small 

 rounded projection or horn, not perforated, but hollow, as may be seen 

 by turning up the hood and looking at its under side. These two little 

 horns curiously bring to mind the ear-like appendages in Conchoderma 

 aurita (Otion), but these latter are perforated, open into the sack, and 

 point outwards. The peduncle-formed body answers, as we shall 

 presently see, to the main part of the shell in Tubicinella, and the 

 hood, as it would appear, to the lips of the sack-aperture, which pro- 

 ject between its scuta and terga ; of these valves there is not here a trace. 

 The whole surface is smooth, and is formed by rather thin membrane, 

 of an orange colour ; but from the colour of the underlying corium, 

 the whole appears of a dark chocolate red, the reflexed hood being 

 rather lighter coloured. It is singular how closely the colour resembles 

 that of some dark varieties of the above-mentioned Conchoderma aurita, 

 and likewise of Anelasma squulico/a, both pedunculated Cirripedes, 



