204 B ALAN ID. E. 



var. d 'Orbignii, it would, I conceive, be preposterous to found a 

 species on this one character. In the animal's body, every part 

 agrees perfectly with that of var. communis. 



Lastly, we come to var. d'Orbignii (PL 1, fig. I): until quite re- 

 cently I did not even suspect that this form was only a variety of B. 

 tintinnabulum : I have examined a great number of specimens in Mr. 

 Stutchbury's collection, which had come attached on a vessel from 

 Java, and likewise a few other specimens in other collections. They 

 all closely resemble each other in shape, and even in size, and differ 

 only in tint of colour, and in the surface being either very smooth, or 

 longitudinally ribbed, sometimes with rugged, sharp points. From this 

 circumstance — from the peculiarity of the tint, with the tips of the pa- 

 rietes and one side of the radii perfectly white — and from the obliquity 

 of the summits of the radii, I was led to think this form specifically 

 distinct. But the colour does not differ from that of some other varieties 

 of B. tintinnabulum; the circumstance of the colour being uniform or 

 not striped, is common to the sub-varieties of several varieties, and the 

 white tips to the parietes, and the white borders to the radii, result 

 simply from the shell, whilst young, having been wholly white, and 

 this is not rarely the case with var. communis. Dismissing, therefore, 

 colour, it will be found that hardly any other characters remain by 

 which this form can be separated from var. occator; in both the sum- 

 mits of the radii are oblique, in both the sheath is coloured in nearly 

 the same manner, in both the opercular valves, especially the terga 

 (PL 2, figs. 1 m, 1 ?i), resemble each other ; the scuta, however, are 

 smooth in var. d' Orbignii and rough in var. occator. This latter form, 

 certainly, cannot be specifically separated from var. intermedins, and 

 this assuredly is only a variety of B. tintinnabulum. Hence I am led 

 to conclude that Balanus d' Or big nii of Chenu, peculiar as its whole 

 aspect is, must be ranked only as a variety of B. tintinnabulum; its 

 oblique radii resulting from the same cause, whatever that may be, 

 which has given this structure to var. intermedins and occator ; and 

 its peculiar colouring to having been exposed (owing probably to 

 having been transported on vessels) to different conditions, whilst young 

 and old. 



2. Balanus tulipiformis. PI. 2, fig. 2 a — 2 d. 



Balanus tulipiformis ex corallio rubro. Ellis* Philosoph. 



Transactions, vol. 50 (1758), tab. 30, fig. ]0. 

 Lepas tulipa. Poli. Test, utriusque Sicilian, tab. 5, fig. 1 et G 



(1791). 

 Balanus tintinnabulum (var.) Chenu. Illust. Conch., tab. 3, f. 5. 



* According to the letter of the Rules of the British Association, Ellis's 

 name ought to be retained, as it was published in 1758, the same year daring 

 which the 10th edition of the ' Systema Natural appeared, in which edition the 



