456 BALANCE. 



Var. (b) : Shell elongated, sub-cylindrical; sutures obliterated ; sur- 

 face much corroded ; orifice almost circular. 



Var. (c, communis) fig. 1 c, \ e, I h : Shell conical, folded, some- 

 times covered by membrane ; radii developed, narrow ; orifice sub- 

 hexagonal, toothed. 



Var. (d, fragilis) fig. 1 d: Shell conical, smooth, thin ; compartments 

 easily separable, pale-coloured ; radii developed, narrow ; orifice large, 

 toothed, sub-hexagonal. 



Var. (e, depressus) fig. lb, \ g, \ h: Shell much depressed, surface 

 much corroded, smooth : alee largely exposed, marked by lines of growth : 

 radii not present ; parietes on the under side often supported by pillars; 

 orifice sub-hexagonal. 



Hob. — Southern shores of England, Ireland, Isle of Man, Mediterranean, 

 Madeira, Cape de Verde Islands, Southern United States (Charlestown), West 

 Indies, Brazil (Bahia), Rio Plata (Guritti Island), Red Sea, Philippine Archi- 

 pelago, Coast of China, Gulf of Corea, Oregon or Northern California. 



This species is very widely distributed and extremely 

 common. On the coast-rocks of the southern shores of 

 England it is, in parts, even more numerous than the 

 Balanas balanoides, with which it often grows mingled. 

 As already stated, it is often confounded in British collec- 

 tions with this species of Balanus, under the name of 

 Balanus pimctatus; that Montagu had this Chthamalus in 

 view, when describing his Lepas punctatus, is certain, from 

 his original specimen in the British Museum, but whether 

 this was the case with his predecessor, Pulteney, in the 

 Dorset Catalogue, I do not feel so sure. Chthamalus 

 stellatus varies, as we shall immediately see, extremely in 

 appearance. Some of the varieties, as var. depressus, which 

 in external aspect are especially distinct, I have no doubt 

 are reallv varieties, but whether this is the case with some 

 of the forms from the more distant localities, is a little more 

 doubtful; but I beg that it may be observed, that I have, 

 in the case of every one of the varieties, and of all the 

 specimens from distant localities, cleaned with potash and 

 most carefully examined the disarticulated valves, and like- 

 wise dissected the included animal's body. 



General Appearance. — British specimens are usually conical, and 

 have their walls folded, corroded in their upper parts, with the radii 

 not developed, and the sutures more or less obliterated ; in this state 

 the orifice of the shell is entire, and very broadly oval : I have seen 

 specimens in this condition from Madeira, Brazil, and the Gulf of 



