160 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 7 



tentacular cirri, the last 34 to 41 with setae and acicula (pi. 29, fig. 

 1). Length in life 6.5 mm, width without setae about 0.5 mm. Color 

 in life salmon pink anteriorly, more or less translucent posteriorly, the 

 proventriculus clear, visible through the first 7 segments, resembling a 

 syllid in this respect. No teeth or jaws have been observed. 



Prostomium broadly rounded anteriorly, without eye spots or 

 paired pigmented areas, but with a small dark blotch medially near the 

 posterior margin (pi. 29, fig. 1). A pair of cirriform antennae directed 

 anteriorly but inserted ventrally, and a pair of minute (biarticulated?) 

 subglobular, colorless palpi on the ventral side, near the oral aperture. 

 The precise nature of the palpi is difficult to ascertain because of their 

 small size and soft structure. First 3 segments with longer, simple dor- 

 sal cirri and smaller ventral cirri, resembling the prostomial antennae 

 in form. 



Parapodia unequally biramous (pi. 29, fig. 2), the notopodium with 

 a flattened dorsal lobe, closely appressed to the neuropodium, appear- 

 ing scalelike, and provided at its distal end with a simple, dorsal cirrus. 

 A weak, colorless aciculum is embedded in the dorsal lobe (pi. 29, fig. 

 2). The neuropodium is much larger and longer. It contains a single, 

 pale, heavier aciculum, and 4 to 7 composite, falcigerous setae. The 

 ventral cirri are simple, cirriform, and resemble the dorsal cirri, but 

 are longer. Anal cirri 2, flattened, short, only slightly longer than the 

 last segment, inserted side by side (pi. 29, fig. 1). 



Setae, present only in the neuropodia, are composite, the shaft 

 smooth, with a heterogomph articulation; the appendage falcigerous, 

 temiinates in a simple tooth, the cutting edge bordered with fine, 

 minute hairs (pi. 29, figs. 3, 4). The superiormost setae are larger, 

 stronger (pi. 29, fig. 4), and have a longer appendage than those more 

 ventrally (pi. 29, fig. 3), but all resemble one another. 



Hesionella mccullochae is named for Dr. Irene McCulloch, active 

 and stimulating supporter of scientific pursuits, and under whose direct 

 interests these studies have been made possible. It is a great pleasure to 

 dedicate this species to her. 



Holotype.— AHF no. 21. 



Distribution. — Hesionella mccullochae has been found only in the 

 burrows or coarsely constructed tubes of a common, intertidal species of 

 Lumbrineris (see below), always closely associated with the host, but 

 not actually attached. Normally, it lies along the body of the host in 

 the region of some of the median segments. In size, it is greatly dwarfed 



