(sect, f), balanus inclusus. 299 



toothed, large, sub-trigonal; walls either smooth or longitudinally folded; 

 the elongated specimens are most apt to be smooth. The Radii are 

 narrow and oblique. Diameter of largest specimen above three- 

 quarters of an inch. 



Scuta, with the lines of growth moderately prominent ; the internal 

 surface of the valve has been ill preserved ; but a very prominent, 

 hardly reflexed, articular ridge, can be distinguished, as well as the 

 absence of an adductor ridge. Terga, with no distinct longi- 

 tudinal furrow running down the valve : spur short, bluntly pointed, 

 narrow, about one fifth or one sixth of width of valve ; placed at above 

 its own with from the basi-scutal angle ; the basal margin, on each side 

 close to the spur, curves towards it. Internally, all that can be distin- 

 guished, is that the articular ridge is prominent. 



Parietes ; their inner surfaces appear to have been nearly smooth ; 

 the absence of parietal pores could be made out only by polishing a 

 transverse section. The Radii are narrow, and have their upper margins 

 very oblique and rather smooth : in the elongated varieties the sutural 

 edge appears to be almost absolutely smooth ; in the conical specimens 

 it is slightly crenated, the septa being apparently not denticulated. In 

 living species we have a similar variation in the state of the sutural 

 edges of the radii, in B. balanoides and crenatus the edges being much 

 smoother in much elongated specimens than in other varieties. The 

 alee have their upper margins less oblique than those of the radii, with 

 their sutural edges barely crenated. The Basis is either flat, or, in the 

 elongated specimens, deeply cup-formed ; in section it can be seen to 

 be finely and irregularly porose. 



45. Balanus inclusus. PL 8, fig. 10 a— 10 c. 



Shell reddish-brown : radii broad, with their upper mar- 

 gins not oblique, or only moderately oblique ; sutural edges 

 with plainly denticulated septa : basis porose, Scutum loith- 

 out an adductor ridge ; tergum luith the spur rather narrow. 



Var. (a) (PI. 8, fig. 10 b, 10 c), with the shell elongated in its 

 rostro-carinal axis; basis narrow, clasping the stem of a zoophyte; 

 lateral compartments much broader than the almost linear rostrum, 

 carina, and carino-lateral compartments. 



Far. (b), with rough longitudinally folded walls, and with the 

 summits of the radii forming an angle of about 45° with the basis. 



Fossil in Coralline Crag, Sutton and Gedgrave; attached to foliaceous 

 Bryozoa ; Mus. S. Wood, Bowerbank. Var. a. Coralline Crag, Sutton, attached 

 to cylindrical branches of corals ; Mus. S. Wood. Var. b. attached to shells, 

 Osnabruck, Hanover, Mus. Lyell ; Biinde, Westphalia, Mus. Krautz. 



