XORTH AMICRK'AX EARLY TERTIARY BRYOZOA. 181 



The zooecia have large opoin. A gymnocyst and a cryptocyst are more or 

 Jess developed. The mural rim bears distally one or two pairs of spines and 

 laterally a membranous scutum. The distal wall, consisting of a horizontal, basal, 

 and an obliquely ascending frontal part, has usually numerous small, scattered, 

 uniporous septnlae basally, while the distal half of each lateral wall has one 

 multiporous septula. Besides dependent avicnlaria, found in most species, vibracula 

 may also occur on the basal surface of the zoarium. and these are connected with 

 the zoarium by an independent wall. The ovicells are generally hyperstomial. 

 As a rule radicular fibers occur, sometimes springing from a septula (or a dietella), 

 sometimes from a separate chamber connected with a vibraculum. The zoaria are 

 always free, very branched, most frequently with uni- or few-seried zooecia. gen- 

 erally consisting of a single layer and in most cases jointed by means of chitinous 

 transverse belts. (After Levinsen. 1909). 



Figure Hi gives a summary of the most important anatomical features in this 

 family. No trace of the scutum is left <m the fossil forms, but its presence is 

 revealed by a small pore situated on the mural rim. American Tertiary specimens 

 are rare, small, and very fragile, and as a result we have been unable to make any 

 detailed studies of the family. 



The principal genera of this family are : 



Caberea Lamouroux. 1816. 



Cdberitlla- Levinsen, 1909. 



( 'audit Lamouroux, 1816. 



Van Beneden. 1814. 

 Verril, 1879. 



Hoplitella Levinsen, 1909. 



Rhabdosoum Hincks, 1882. 



Mi nipca Lamouroux, 1816. 



The two genera Caberea and x< n< /><><; llnr'/a alone are represented in the Ameri- 

 can collections studied. CanJn and Xmijw< llui-ia are very similar. Levinsen 

 distinguishes these genera by their ovicells and Waters by their articulation. 



Genus SCRUPOCELLARIA Van Beneden, 1844. 



1X44. XiTi/iHiri-iliiria VAN BENEDEX. Recheivlies sur I'ortmnisation des Lajruncula et 1'liis- 

 toire uaturelle des different* Polypes Bryo/oaires, Nouveaux Memuires de 1'Acadeuiie 

 Royale de Bnixelles. vnl. 18. \>. 44. 



Zoarium jointed. Zooecia numerous in each internode, rhomboid; opesia with 

 or without scutum; a sessile avicularium at the upper, outer, lateral angle, a vibrac- 

 ulum at the lower outer angle, and generally a sessile avicularium on the front sur- 

 face of each zooecium. (Robertson.) 



Accepted genotype. Scrupocellaria x>-/->ijni.i(t Linnaeus. l~.">s. 



Range. Lutetian-Recent. 



