FOSSIL CIRRIPEDES, 



529 



S. arcuatum (text-fig. 64, 3) and S. irilineatum (text-fig. 64, 4) 

 the parietes reach to the basal margin, and in my opinion the 

 intraparietes will be found to be developed in aS'. accumulatum 

 (text-fig. 64, 2) as in those species, since *S'. accuvmlatum is 

 similar in its general external form. The only carina known 



Text-fig. 64. 



Early types of tlie Carina of Scalpellum. 



1 a-5 a, side view ; 3 S, 4 5, 5 5, inner view ; 1 c-5 c, transverse section near apex. 



t., tectum ; p., parietes ; i.p., intraparietes. 



of S. accumulatum is embedded in such a hard matrix that it is 

 impossible to expose its inner siirface without danger to the speci- 

 men, so that the matter must here remain until further specimens 

 are forthcoming. 



So far, then, we have proved the existence of intraparietes in 



