NO. 2 HARTMAN, BARNARD: BENTHIC FAUNA OF DEEP BASINS 161 



Genus STREBLOSOMA Sars, 1872 



Streblosoma crassibranchia Treadwell, 1914 



Several anterior ends were taken in San Pedro Basin; they may be 

 juvenile or vegetative stages of this species, which is common in shal- 

 lower depths (unpublished data). 



Genus THELEPUS Leuckart, 1849 



Thelepus setosus (Quatrefages) 1865 

 Berkeley and Berkeley, 1952, p. 83, figs. 168, 169. 



This species was taken in San Pedro Basin ; it is more abundantly 

 present in shallower bottoms. Its geographic distribution is cosmopolitan 

 (Berkeley and Berkeley, 1952, p. 83). 



Genus LEAENA Malmgren, 1866 



Leaena caeca, new species 

 Leaena, unknown sp. Hartman and Barnard, this volume, p. 63. 



The type is selected from Santa Catalina Basin (Sta. 2850) in 620 

 fms. Other specimens are from the same area but in shallower, above- 

 sill depths. An ovigerous adult measures 18.5 mm long and 1.2 mm 

 wide; it consists of 16 thoracic and 13 abdominal segments; a posterior 

 end is lacking. These abdominal segments measure about a third of the 

 total length of the body. The body narrows abruptly between the thorax 

 and abdomen, at the transition region. There are no eyes and no bran- 

 chiae. The tentacular base is continued across the dorsum and provided 

 with 9 to 12 pairs of cirriform tentacles inserted on a semicircular base. 

 The lower lip is almost continuous in a transverse line with this base. 



The first 2 visible segments are complete rings. Each is a little longer 

 than the following segments and each has a short, lateral expansion but 

 no true lappets. The third segment is the first setigerous, and the fourth 

 is the first uncinigerous. The thorax thus consists of 16 setigerous and 

 15 uncinigerous segments. 



Ventral scutes are present on all thoracic segments but the last seven. 

 Those on the first 2 segments are largest, and later ones decrease in 

 width gradually to the last one, which is longer than wide. Thoracic 

 neuropodia have uncini in double rows. Those of the last 6 segments 

 differ from the more anterior ones in being located ventrolateral^ and 



