1910] Robertson: Cyclostomatous Bryozoa. 261 



These eaneelli, or alveoli as they are variously called, arc Eormed 

 by secondary, calcareous thickenings or septa which begin to 



form very early in the history of the colony, and according to 

 llarnicr ( '96) hear a close relation to the growth of the ovicell. 

 This investigator says "the presence of eaneelli bet ween the rows 

 of zooecia is au indication that the ovicell is developing, even 

 although no other evidence is obtained of its presence." Accord- 

 ing to the same authority, each colony of Lichenopora possesses 

 hnt one ovicell. the aperture of which is formed secondarily. A 

 second characteristic is frequently shown in the shape of the 

 zocecial apertures, which frequently end in a tapering point 

 either single or bifid. 



There are three species 0/ Lichi nopora on the Pacific coast 

 distinguished in the key given below partly by their habit of 

 growth, partly by the oceeial aperture. 



KEY TO THE SPECIES OF LICHENOPORA. 



1. Zooecia in single rows; oceeial aperture flaring 



1. Zocecia not in single rows; ooecial aperture not flaring 3 



2. Rows of zocecia radiating regularly in alternating single series 



L. radiata 



2. Rows of zocecia radiating irregularly, in more or less alternating 



series L. verrucaria 



3. Zooecia in connate bundles, irregularly radiating; ooeciopore 



smaller than the aperture of a zocecium L. californica. 



102. Lichenopora californica (d'Orbigny) Conrad. 



PI. 25, figs. 48, 49. 



Unicavea californica d'Orbigny, 1852, p. 972. 

 Lichenopora californica, Conrad, 1S55, p. 44. 

 Lichenopora californica, Gabb and Horn, 1862, p. 176. 

 Discoporella californica, Husk. 1875, p. 32, pi. 30, fig. 5. 

 Lichenopora californica, Waters, 1890, p. 283, pi. 15, fig. I. 



Zoarium discoid, adnate, adhering to kelp, eel grass, etc.; 

 colonies small, oval or circular (pi. 25. fig. 49). Zocecia connate 

 in radiating series, one, two, or three rows of zocecia in each 

 series (fig. 48) erect, almost vertical, throughout more than 

 half their length, the central part of the colony and the portions 

 between the zooecia, therefore, much depressed. Ocecium (oe.) an 



