NO. J HARTMAN : SUBMARINE CANYONS 83 



San Pedro sea valley, 319 m (21). 



Newport en, 272 m (7), 420 m (10), 478 m (17). 



Amygdalum pallidulum (Dall) 1916 

 Redondo en, 76 m (240) . 

 La Jolla en, 545 m (8). 



This nest-building mytilid was redeseribed by Soot-Ryen (1955 

 p. 69). 



Yoldia scissurata Dall, 1898 

 Redondo en, 148 m (27). 

 Newport en, 170 m (2 large), 211 m (2) measure 30 by 14 mm. 



Solemya panamensis Dall, 1908 

 Santa Monica en, 116 m (21 large). 



Its oeeurrenee in polluted areas is of some interest, sinee it thrives 

 where few other mollusks are found. 



Macoma incongrua (Martens) 1865 



The greatest concentration of this deepwater pelecypod occurred 

 in Redondo en, 148 m (323). 



Acila castrensis (Hinds) 1843 

 Hueneme en, 177 m (4). 

 Muguen, 177 m (68). 



Newport en, 170 m (26), 211 m (110, measure about 11.5 mm 

 long ; some are penetrated by a drill) . 



Additional Notes on GASTROPODS. 



Mitrella permodesta (Dall), 1890 



Redondo en, 611m (30). 



Newport en, 553 m (27) , 642 m (49) . 



La Jolla en, 545 m ( 1 ) , 637 m ( 10 or more) . 



Additional Notes on SCAPHOPODS. 



Dentalium rectius Carpenter, 1864 



Monterey en, 168 m (5) ; 260 m (present) ; 410 m (16 living and 

 many dead shells). 



Hueneme en, 209 m ( 47 ) , 478 m ( 5 ) . 

 Muguen, 177m (37). 

 Redondo en, axis, 246 m (32). 



