58 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 7 



Parapodia are long throughout, the notopodium at first shorter than 

 the neuropodium (pi, 11, fig. 136) and gradually increasing in length 

 so as to extend distally beyond the neuropodium (pi. 11, fig. 138). The 

 notopodium is distally vesicular and terminates in a short cirrus, dorsal 

 to the setal fascicle. Neuropodia are obliquely truncate, terminate dor- 

 sally in a triangular lobe in which the aciculum is embedded. Acicula 

 are pale, not extending beyond the fleshy lobes. Ventral cirri are cirri- 

 form, taper distally, and are directed ventromedially. They extend dis- 

 tally beyond the neuropodium to which they are attached. Anal cirri 

 include a single long, slender filament about as long as the last 12 

 segments, and a shorter, similar filament only about half as long. 



Notopodial setae are pale, long, slender, directed dorsally and 

 curved somewhat over the dorsum. Under high magnification they show 

 a finely serrated edge (pi. 12, fig. 147). The neuropodial setae include 

 a supraacicular fascicle, emerging from the dorsal side of the neuro- 

 podium, and a heavier subacicular fascicle. The superior fascicle consists 

 of about 9 finer, composite setae at the anterior side and 12 to 15 pro- 

 gressively coarser composite setae posteriorly. A few (about 4) have 

 shorter, most of them have longer, appendages (pi. 12, fig. 146). In 

 addition, there are about 7 shorter, simple, spinose setae (pi. 11, fig. 

 140) in the anterodorsal part of the fascicle. The subacicular fascicle 

 includes a few (about 4) stouter, short-appendaged, composite setae, 

 and a great many (40 to 50) much finer, longer, composite setae. These 

 have a long, slender, articulated appendage with bifurcated tip (pi. 11, 

 fig. 137). The shaft is spiny, hence the specific designation. 



No tube or investing sheath has been found with, or on, any of the 

 individuals. Indications are that it burrows through a soft substratum. 



Eusigalion spinosum differs from E. vazensis Augener, the only 

 known species in this genus, in its prostomial proportions (Augener, 

 1918, pi. 2, fig. 14), its much greater size, in having spinose setal shafts, 

 and in its elytral details. It resembles Sigalion ovigcrurn Monro (1924, 

 p. 47; 1930, p. 101) in having long, slender neuropodial setae, but in 

 the latter the prostomium lacks a median prostomial antenna. 



A single specimen from Ballast Point, San Diego, California, in the 

 collections of the University of California, labelled Sigalion pourtalesii 

 (Treadwell, 1914, p. 183) is a Eusigalion, identical with the species de- 

 scribed above. The genus, Sigalion Audouin and M. Edwards, is there- 

 fore not known to be in California waters. 



Holotype. — AHF no. 8. 



