DESCRIPTION OF SPECIES 55 



Branchial sac. There are about twenty-four simple oral tentacles of alternating sizes (Text- 

 fig. 10C). The dorsal tubercle is very simple and has an oval transverse slit (Text-fig. ioC, d.t.). 

 Twenty-seven to thirty-four rows of narrow stigmata are present, each row usually containing forty 

 to fifty stigmata. There are no parastigmatic transverse bars. The hooked dorsal languets (Text- 

 fig. 10 D, d.l.) are wide at the base and taper rapidly to a point. The languets towards the posterior 

 end of the branchial sac become progressively larger. 



B 



4.0 mm 



I ii»»»*l 



2.0 



Text-fig. 10. Ritterella vestita sp.n. (St. 934): A, colony; B, zooid; C, oral tentacles and dorsal tubercle; D, part of roof of 

 branchial sac, showing dorsal languets; E, transverse section of stomach; F, part of gut. 



