UNIVERSITY OF CALIFORNIA PUBLICATIONS 



IN 



ZOOLOGY 



Vol. 4, No. 5, pp. 253-344, Pis. 14-24 May 27, 1908 



CONTEIBUTIONS FROM THE LABORATORY 



OF THE 



MARINE BIOLOGICAL ASSOCIATION OF SAN DIEGO. 



XX. 



THE INCRUSTINe CHILOSTOMATOUS 



BRYOZOA OF THE WEST COAST 



OF NORTH AMERICA. 



BY 



ALICE ROBERTSON. 



This paper completes the report on the CJtilostoniafa in the 

 present collection of the University of California, and constitutes 

 the second of the series of papers on the bryozoa of the Pacific 

 Coast begun by the writer ( '05 ) in a report on the non-incrusting 

 and flexible Chilostomes of that region. Since no sharp distinc- 

 tion can be made between those Chilostomes which merely incrust, 

 and those which besides may form calcareous, foliaceous colonies, 

 or which grow erect and branching, all the non-flexible Chilosto- 

 matous species are included under the present title. 



There are included in this report ten families, eighteen genera, 

 forty-five species, and three sub-species. Of these six species and 

 one sub-species are new. New facts are added to our knowledge 

 of many species, more especially of those restricted to this region. 

 IMo.st of these latter were reported by Hincks ( '80- '84), frecpient- 

 ly from scanty material so that the descriptions were necessarily 

 meager and lacking in details. Of the whole number reported in 

 this paper, nineteen species and one sub-species are restricted to 



