Proceedings of 

 the United States 

 National Mviseum 



SMITHSONIAN INSTITUTION . WASHINGTON, D.C. 



Volume 122 1967 Number 3593 



A NEW SPECIES OF VICTORELLA 



FROM SOUTHERN CALIFORNIA 



(BRYOZOA: CTENOSTOM ATA) » 



By William C. Banta^ 



A new species of ctenostome polyzoan, Victorella argilla, has been 

 discovered in great abundance in seven southern California locations. 

 It exists in two growth forms, similar to the growth forms of Victorella 

 pavida Kent. In the younger stage (form A) the animal is nearly 

 indistinguishable from certain species of Arachnidium, whereas the 

 older stage (form B) shows closer affinities to Nolella and Q'yptopoly- 

 20011. In many respects, especially the budding of new zooids from 

 the apertural papilla, the animal is a typical Victorella. In others, 

 however, it is unique: it inhabits marine waters, not brackish ones as 

 do other Victorellas, and it possesses peculiar fdiform processes modi- 

 fied for the accumulation of sediment. 



The colony consists of more than one-half inorganic matter tightly 

 bound to the zoecia by an adhesive. The spreading zoaria appear 

 early in the pattern of ecological succession of some environments and 

 effectively crowd out many competitors. It is the most abundant 

 animal species in certain areas. 



This paper would not have been written without the patient efforts 

 of Robert R. Given, to whom credit should be given not only for the 



> Contribution no. 281) of the Allan Hancock Foundation. 



2 Department of Biology, University of Southern California, Los Angeles 90007. 



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