190 



TEREBELLARIA. 



of growth of these is shown in the longitudinal section (Fig. 16) : 

 upon the summit is a layer of young tubular zooscia, which in 

 section agree with those of a Reptomultisparsa. Below this the 



FIG. 16. Longitudinal section through end of branch of Terebellaria 

 ramosissima, Lamx. x 10 dia. Great Oolite : Bath. D. 1762. 



FIG. 17. Transverse section across branch of Terebellaria ramosissima, 

 Lamx. x 10 dia. Great Oolite: Bath. D. 1762. 



section passes longitudinally along the zocecia: it shows them 

 to be simple, JBerenicea-\ike tubes, which are sharply reflexed 

 downwards around the stem. Many of these zooecia are cut off 

 by the overgrowth of the layer next above them, and are thus 

 aborted into dactylethraB. 



