16 PEOCEEDIISrGS OF THE NATIONAL MUSEUM vol. 72 



The opercular valve is somewhat higher than broad and Httle 

 thickened. The seta of the vibraculum is falciform. When the 

 ectocyst covers the interior face, the large pores appear by transpar- 

 ency much smaller and circular. This deceiving aspect enables one 

 to suppose the existence of two species. The vibraculum belongs to 

 the proximal zooecium. 



Biology. — The calcite of our living specimens is white but their 

 ectocyst is light colored. The color of Osburn's specimens is "horn 

 brown, due mainly to the chitinous bristles which form the mandible 

 (seta) of the vibracula." Our specimens, like those of Osburn, are 

 always free. The following observation of Osburn is very important: 

 " When touched the bristles stand erect for some time." It confirms 

 our views on the physiologic functions of the 

 vibracula and of the setiform avicularia. These 

 are organs of relation either with the surrounding 

 medium or between the cells themselves. 



This is an equatorial species which in the 



Mediterranean does not extend beyond the 



thirty-eighth parallel. Its presence in the Gulf 



of California indicates an old passageway be- 



FiG. 2.-CUPULADRIA CANA- ^^ecn thc Atlautic and the Pacific. 



EiENsis Busk, 1852. A. C. cauariensis is one of the rare species char- 



Srr AKSc?J:;jn: ^cteristlc of the abyssal deeps. The mobiUty of 



Opercular valve and the colony is Occasioned by the presence of nu- 



APERTURAL scLERiTE, X 85 j^^rous vibracula which permits them to escape 



being covered with mud. The bathymetric dispersion is very great, 



for it has been dredged on the sands of little depth at the Canary 



Islands. 



The reader will find a detailed study of the genus Cupuladria in 

 our volume on the Philippine bryozoa. 



Occurrence.— Albatross Station D. 2405, Gulf of Mexico, 28° 45' 

 00" N.; 85° 02' 00" W.; 30 fms.; gray sand, broken 

 coral. 

 Albatross Station D. 2639, Straits of Florida, 25° 04' 



50" N.; 80° 15' 10" W.; 56 fms.; coral sand. 

 Atlantic, Fowey Light, 15 miles south of Miami, Fla.; 



40 fms. 

 Tortugas, 16 meters (Osburn); Florida, 16-21 meters 



(Smitt). 

 Pliocene : Minnitimmi Creek, Bocas Island, x41mirante 

 Bay, Panama. 

 Plesiotypes.— Cat. No. 7829, U.S.N.M. 



