(sect, a), balanus tulipiformts. 205 



Shell dark rose-coloured, sometimes tinged with purple ; 

 orifice toothed. Scutum externally very smooth, covered by 

 membrane. Tergum ivith distinct crests for the depressor 



muscles. 



Hub. — Sicily, Malta, Malaga, (associated with B. perforatus), Madeira. 

 Often growing in clusters and associated with Bachylasma giganteum. Attached 

 to Millepora aspera, oysters, and other shells. According to Poli, an inha- 

 bitant of deep water; yet in mus. Cuming there are two fine specimens 

 attached to the always floating Lepas anatifera. Mus. Lowe, Macandrew, 

 Stutchbury. 



General Appearance. — Shell tubulo-conical or conical: orifice large, 

 toothed, approaching to pentagonal. Surface moderately smooth, 

 naked. Colour rosy, or tile-red, with a slight tinge of purple; or 

 beautiful rich purple. Radii nearly as dark as, or darker than, the 

 parietes. The portion of the alse seen externally is generally white. 

 Internally the whole shell is nearly white. Generally the tints outside 

 vary in transverse fascise ; sometimes there are very fine, dark, lon- 

 gitudinal lines. Largest specimen (from Malta), 1*4 of an inch 

 in basal diameter ; usually full-sized specimens are about three quarters 

 of an inch in basal diameter. 



Scuta (PI. 2, fig. 2 a, 2 c) very smooth, with the growth-ridges very 

 little prominent, sometimes there are obscure traces of longitudinal 

 striae ; surface covered by an unusually thick and persistent yellow 

 membrane : valve narrow, with the upper part commonly reflexed : 

 the basal margin forms, with the occludent margin, a smaller angle 

 than is usual : the tergal margin of the valve is rectangularly inflected, 

 instead of being, as is usual, merely bowed inwards. Internally, the 

 articular ridge is rather prominent. The depth of the slight pit for 

 the lateral depressor muscle is variable ; it sometimes includes a minute, 

 central, longitudinal ridge. 



Terga (2 b, 2 d) : the longitudinal furrow is deep, with the sides 

 folded in ; the spur is placed at about its own width from the basi- 

 scutal angle ; it is moderately long, with its lower end obliquely 

 rounded off; but the length, breadth, and precise outline of the lower 

 end varies a little. The basal margin on the opposite sides of the 



binomial method was first used. But as Ellis himself did not then know of, or 

 follow this method, it might be disputed whether, according to the spirit of the 

 law, his name ought to stand. The only other name given to this species is 

 that of iulipa, affixed by Poli in 1791, but this name had been previously used by 

 Miiller in 1776, and by Chemnitz in 1785, for another species, the B. Humeri 

 of this work ; and likewise, also previously to Poli, by Bruguiere in 1789, for 

 still another species, viz., B. tintinnabulum of this work : under these compli- 

 cated causes of confusion, I think it is highly advisable to adopt Ellis's name. 

 I may add that the B. tulipa of Mr. G. B. Sowerby is the B. tintinnabulum. of 

 this work. It is possible that the B. conoicles of Brown, ' Illustrations Conch.' 

 (1st edit. pi. 6, fig. 7), may be our present species; but without details of 

 structure it is hardly possible to identify, in many cases, the species of Balanus. 



