FOSSIL CIREIPEDES. 



529 



S. arcioatum (text-fig. 64, o) and S. trilineatum (text-fig. 64, 4) 

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

 intraparietes will be found to be developed in S. accumulatum 

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

 similar in its general external form. The only carina known 



Text-fig. 64. 



Early types of the Carina of Scalpellum. 



1 «-5 a, side view ; 3 J, 4 S, 5 6, inner view ; 1 c-5 c, transverse section near apex. 



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



of S. acciomulatum is embedded in such a hard mati'ix that it is 

 impossible to expose its inner surface 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 



