382 
PACIFIC SCIENCE, VoL XXII, July 1968 
Fig. 3d. Bathymetric profiles Nos. 16-20. See Figure 1 for locations. 
70 meters, but usually landward of about 75 
meters another terrace level commenced, prob- 
ably equated to the Penguin Banks Shelf of 
55 meters depth as defined by Steams (1966). 
The inner edge of this shelf was not explored 
with the "Asherah.” 
Both the Mamala and Penguin Banks shelves 
were very flat and, approximately south of 
Makua Valley, were covered extensively with 
patches and channels of sand. These masses of 
sand were generally irregular but connected 
into river-like masses 30 or more meters in 
width, which continued across the shelves and 
through cuts in the escarpments down to the 
diving limit of the "Asherah.” On the Mamala 
and Penguin Banks shelves, the sand channels 
and sand patches were rippled; generally the 
ripples were elongated normal to the channel 
axis irrespective of the meandering of the i 
channel. Usually the sand bodies were not be- 
low the general level of the shelves, except ! 
where the sand bodies passed through the 
various escarpments. 
Lithology 
Due to the limitations of the "Asherah” it 
was not possible to collect rock samples at the 
time visual observations were made. Nor was 
it possible to use heavy rock dredging gear j 
aboard the "Teritu.” Consequently, an adequate 
lithologic sampling program could not be 
undertaken. 
Nevertheless, rock samples were dredged 
