16 FOSSIL CIRRIPEDIA. 



3. Balanus spongicola, Tab. I, fig. 3a — Se. 



Balanus spongicola. Brown's Illustrations of the Conchology of Great Britain (1827), 



pi. 7, fig. 6 : 2d edit. (1844), pi. 53, figs. 14—16. 



B.parietibus et basi, sed non radiis poris perforatis ; parietibus plerumque lesvibus, 

 roseis ; orificio dentato ; scuto longitudinaliter striato ; tergum, apice producto, sine sulco 

 longitudinali, calcare truncato, ± valva latitudine. 



Parietes and basis, but not the radii, permeated by pores ; parietes generally smooth • 

 shell pink ; orifice toothed ; scutum longitudinally striated ; tergum, with the apex pro- 

 duced, without a longitudinal furrow ; spur truncated, about one third of width of valve. 



Fossil in Coralline Crag ; Sutton ; Mus. S. Wood. 



Recent on the South coast of England, and Tenby in South Wales ; Algiers ; Madeira ; Lagulhas Bank, 

 Cape of Good Hope. 



I have seen only a single specimen of this species, which I picked out of a mass of 

 specimens of the extinct Bal. inclusus, collected by Mr. Wood, in the Coralline Crag at 

 Sutton. This one specimen was perfect, and included the opercular valves j it even 

 partially retained its rosy colour : it was *3 of an inch in basal diameter, and therefore 

 exactly half the size of the largest recent specimen which I have seen. It was in every 

 respect perfectly characterised. I have given drawings, external and internal, of the 

 scutum and tergum from the fossil specimens. In the scutum, the adductor ridge is, 

 perhaps, rather more prominent, and the pit for the lateral depressor muscle rather deeper 

 than in recent specimens ; but these points are extremely variable. The tergum, in its 

 outline, strictly agrees with the European recent specimens, and not with those varieties 

 from the Cape of Good Hope and West Indies ; indeed, in the degree in which the basal 

 margin on the carinal side of the spur slopes towards the spur, it even, perhaps, exceeds 

 the European variety. These valves are fully described in my Monograph on the Balanidse. 

 From the shell alone, as viewed externally, Bal. spongicola, even in its recent state, can 

 hardly be distinguished from Bal. tulipiformis, or from some varieties of Bal. Capensis : 

 I doubt whether this species could anyhow be distinguished in its fossil condition from the 

 young of the fossil Bal. concavus, without the aid of the opercular valves. But in order 

 to give an idea of its general appearance, and as I was compelled to disarticulate the com- 

 partments of the one fossil shell, I have had a fine recent specimen from the Mediterranean 

 engraved on an enlarged scale. 



