17 



February 1955 by Jens Kjiudsen). These showed the presence 

 of some species identical with those in southern Calif- 

 ornia. Many more were lacking from one or the other area, 

 and still others, including the annelid genera, Aglaurides , 

 Chaetacanthus and Hesione « were well represented in the 

 south, but absent in southern California, Cerianthid 

 anemones were abundant and large at Acapulco, but small 

 or of another kind in Santa Monica Bay. 



Quantitative studies made in the Puget Sound area 

 of Washington by Shelford and associates (1935) named 

 many species occurring in shallow (to 105 feet) unpolluted 

 level bottoms. The study was based largely on hard- 

 shelled mollusks, many of which do not occur in Santa 

 Monica Bay, A complex system of classification was 

 described. Some species were called biome prevalents 

 or predominants, others were slow moving influents. There 

 were characteristic species and faciations, and inter- 

 actions of coaction and reaction kinds. The Puget Sound 

 area was described with broad expanses characterized 

 by the dominance of one or a few kinds of species, with 

 clear boundaries existing from one expanse to the next. 

 One restricted area in East Sound, with bottoms in 60 

 to 105 feet, was investigated with a small Petersen 

 bottom sampler which took samples from a tenth of a 

 square meter. The sediments were then screened through 

 a 0,20 mm mesh. From 14 such samples, 68 metazoan 

 invertebrate animals were identified (Weese, In Shelford 



