90 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 7 



The PISIONIDAE constitute a small, little known family, known 

 through only a few records. Their affinities are possibly with the 

 HESIONIDAE on the one hand, and with the scale-bearing chaeto- 

 pods, or more nearly the SIGALIONIDAE, on the other. The pro- 

 boscis is clearly of the scale-worm type. The paired prostomial an- 

 tennae are inserted on the peristomial segment, as in some of the 

 SIGALIONIDAE. In the new genus, Pisionella, there is a well de- 

 veloped median antenna. Notopodia are inconspicuous, but the neuro- 

 podia are stout and well provided with setae. 



Two genera, Pisione Oersted and Praegeria Southern, have been 

 attributed to this family. The type of Praegeria, P. remota Southern, 

 sufficiently resembles the type of Pisione, P. oerstedi Grube, that the re- 

 tention of the genus Praegeria is unnecessary. P. oerstedi Grube and P. 

 remota (Southern) differ from one another in the details of their para- 

 podial and setal structures. 



More recently, Augener (1924, p. 300) described a Pisione, P. ger- 

 manica, from the North Sea, which agrees with the description of 

 Praegeria remota Southern, from Ireland. 



Pisione contracta Ehlers (1901, p. 64) from Callao, Peru, has been 

 shown to be the same as P. oerstedi Grube (Augener, 1924, p. 298). In 

 conclusion, therefore, 2 valid species are known to occur, Pisione oerstedi 

 Grube, from Peru, Ceylon, and New Zealand (Augener, 1924, p. 298; 

 1926, p. 445) and Pisione remota (Southern) from Ireland and the 

 North Sea. 



The Hancock collections include another species, Pisionella hancocki 

 (described below), clearly of this family, but differing sufficiently in its 

 structure to warrant the erection of a new genus. In several of its char- 

 acters it is more primitive than are the species of the genus Pisione. The 

 prostomial lobe is less reduced, its antennae are cirriform and little 

 modified. 



Genus PISIONE Grube, Ehlers 



Pisione Ehlers, 1901, p. 60. 



Praegeria Southern, 1914, pp. 63-64; Augener, 1926, p. 445. 



Prostomium produced dorsally between the first few segments, with- 

 out attached antennae or other appendages, but with 2 pairs of eye 

 spots in which the 2 of a side may be more or less coalesced. Proboscis 

 with 7 pairs of terminal papillae and 2 pairs of stout, chitinous jaws. 



