NO. 1 



hartman: quantitative survey 



147 



Dr. Norman T. Mattox; four species of enteropneusts were studied by 

 Keith Woodwick (see Appendices, below) . 



The technical details of the equipment are described by Dr. Floyd E. 

 Durham (see Appendices, below). 



The Impoverished Area of San Pedro Basin 



An analysis of the samples shows that there is an area in San Pedro 

 Basin that is characterized by an impoverished fauna (see chart 2) ; it 

 is an approximately lozenge-shaped tract measuring about 8 by 15 miles, 

 with a much smaller area to the north and west. Its outer margins follow 

 rather closely the 425 fathom contour line. Depths range from about 405 

 to 495 fms, or the deepest part of the Basin. The area is bounded by a 

 glass sponge association (see below), especially along the rims where the 

 current may be most rapid. The few animals existing in the impoverished 

 association are almost entirely a chaetopterid annelid, Phyllochacopterus 

 sp., a serpulid, protulid, and less frequently an ampharetid and a glycerid, 

 Glycera branchiopoda. There are often delicate, translucent shells of a 

 Pec ten, few of which have been found living; but many have been seen 

 that were unworn and not long dead. 



The impoverished Phyllochaetopterus association in San Pedro Basin 

 comes from maximum depths in bottoms of very fine oozy mud. The 

 following lists the sample numbers, depth in fathoms, and volumetric 

 measurements of the samples obtained. 



