16 FOSSIL CIRRIPEDIA. 
3. Bauanus sponercona, Tab. I, fig. 3a—3e. 
BALANUS SPONGICOLA. Brown’s Illustrations of the Conchology of Great Britain (1827), 
pl. 7, fig. 6: 2d edit. (1844), pl. 53, figs. 14—16. 
B. parietibus et bast, sed non radiis poris perforatis ; parvetibus plerumque laevibus, 
roseis ; orificio dentato ; scuto longitudinaliter striato ; tergum, apice producto, sine sulco 
longitudinal, calcare truncato, ; valve 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. 8S. 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; it even 
partially retaimed 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 Balanide. 
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. 
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