I9t)8] ■ Robertson. — Incntsting Bryozoa. 315 



rim of the colony (pi. 24, fig. 90) ; rim ereniilated, each crenula 

 occupied by a vibracnlar chamber with its long seta. Zooecia al- 

 ternate, oval or rhomdoiclal, surface granular, plain; in zooecia 

 near the growing rim the middle part of the front wall thinner, 

 and outlined by a row of pores (fig. 91, p.). Operculwm, op., 

 semicircular above, straight below, surrounded by a rather heavy 

 chitinous rim, chi. r., continuous apparently with a similar rim 

 supporting the vibraculum. Vibracular chamber at the distal 

 extremity of each zooecium, large, with a distinct auricular pro- 

 jection on one side ; seta long, when extended along the groove as 

 long as two zocecia. Ocedaf Dorsal surface marked by sulci or 

 grooves which correspond roughly with the radiating rows of 

 zooecia. 



According to Arnold ('03) this species is ciuite abundant in 

 the Pleistocene of Dead ]\Ian's Island, San Pedro, California. 

 It has also been obtained living at a depth of four fathoms near 

 San Pedro and dredged off the Island of Santa Catalina. 



University of California, 



Berkeley, Cal, August 1, 1906. 



