30 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 27 



and 545 m, the bottom is somewhat impoverished, with numbers of 

 species and specimens reduced. In deeper parts a deepwater fauna 

 exists, characterized by brissopsids, some ophiuroids, Maldane cristata, 

 Aricidea rarnosa; and in its deepest parts an abyssal fauna is found ; 

 this includes pogonophores, Ophiacantha normani and some unusual 

 polychaetes. In these respects this canyon shares some characteristics 

 of the next adjacent Coronado canyon (see below). 



CORONADO CANYON 



Eight samples (see Fig. 12) taken in 123 to 1265 meters, range in 

 size from 0.6 cuft in 566 m to 5.74 cuft in 344 m. Biomasses 

 range from a low of 2.4 to a high of 105.7 grams per sample. 

 The analyses resulted in the documentation of 101 species and 843 

 specimens of polychaetes, 13 species of echinoderms, at least 16 mol- 

 lusks, 15 or more crustaceans, and 9 other kinds of animals, or a total 

 of more than 154 species. Largest individuals are Ophiura liitkeni, 

 Glycera robusta, Brissopsis pacifica, Melinna heterodonta and -Asychis sp. 

 Most abundant in a sample were Arnphiodia urtica, in 177 m with 



107 specimens, and Spiophanes missionensis with more than 100, Brada 

 pilosa in 566 m with 63 and solenogasters with 44 specimens. Melinna 

 numbered 36 specimens in 344 meters. 



The shallowest sample, in 123 m, contained chiefly shelf species, 

 and all other samples had either deepwater species or unique kinds. 

 Most unusual were Siboglinum and an oligochaete with prickly epithe- 

 lium at 960 meters. 



SANTA CRUZ CANYON 



Nme samples were taken in 89 to 1624 meters (see Fig. 13) with 

 the large grab sampler;, and one^ other in 800 m with the small one. 

 Size of sample varied from 0.26 cuft in the shallowest depth, to 4.16 

 cuft in the deepest station. Biomasses were highest in 459 meters, 

 where large Brissopsis pacifica comprised the bulk. The shallowest 

 bottoms were shelly sand and silt, which support many kinds of small 

 animals, whereas deep bottoms, from 676 rti down, are mud. Peak 

 numbers are recorded for an onuphid, where 247 juvenile specimens 

 occurred in 89 meters; small chitons with 34 specimens in a rocky 

 bottom at 218 rh ; Tellina carpenteri with 36 and Chaetozone sp. 

 with 244 in 459 meters, and Lciochrides he?nipodus with 25 specimens 

 in 902 meters. 



