362 DISCOVERY REPORTS 



in most zooecia, with two to five tines, and crossing proximal internal spine which is 

 stout, unbranched, and curved across aperture. 



Frontal avicidaria small, absent from many zooecia, slightly larger on median zo- 

 oecium at bifurcation. 



Lateral avicularia absent. 



Fig. 18. A-D. Scrupocellaria frondis Kirkpatrick. A. 31. 12. 9. 7. Dry Tortugas. Basal view showing 

 vibraculum and adjacent structures. B. 31. 12. 9. 7. Dry Tortugas. Frontal view. C. St. 1, Ascension 

 Island. Young colony in slightly oblique basal view. D. 31.12.9.7c. Dry Tortugas. Ancestrula with 

 rootlets and rudiments of first zooecium. Polypide omitted. 

 a. ancestrula, ax.v. axillary vibraculum, r. rootlet, s. seta, v. vibraculum, 1-4, first four zooecia. 



Vibracula (Fig. 18 A). Vibracular chamber not visible in frontal view of branch, 

 longer than wide, with lateral rootlet chamber, whole structure nearly circular, truncated 

 distally by transverse vibracular groove. Seta long and fine. One small vibraculum in 

 axil of bifurcation. 



Ovicells longer than wide, with a few pores connected by radiating sutures. 



Rootlets smooth. 



Remarks. The Discovery specimens agree very closely with the type and with the 

 specimens from the Tortugas figured here. The branches of the lumen of the scutum 

 are sometimes not quite so much recurved. 



