260 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 15 



Orbinia johnsoni differs conspicuously from the genotype O. cuvieri 

 (see above) and most species of the genus in having no ventral or inter- 

 ramal cirri. It is the only known species of the genus from the Americas. 



Distribution.- — O. johnsoni is known from central and southern 

 California south to Port Parker, Costa Rica, in sandy beaches, especially 

 in protected bays or coves; it is intertidal to 3-8 fathoms. 



Genus Phylo Kinberg, 1866 

 Type P. felix Kinberg, 1866 



Includes Aricia in part, and Archiaricia Czerniawsky, 1881. 



Phylo differs from Orbinia (see above) in having the thorax modi- 

 fied into two regions, an anterior one with normal setae and a posterior 

 one with modified spines and special glandular pouches (pi. 23, fig. 2). 

 Anterior segments have long pointed setae and uncini. Parapodial and 

 ventral fringe are usually present on some thoracic or anterior abdominal 

 segments or limited to neuropodia. Ventral fringe is absent in P. nor- 

 vegicus and P. nudus (see below). 



The prostomium is short and conical (pi. 23, fig. 1). The first or 

 peristomial segment is a smooth ring but may be transversely divided 

 so as to appear double (P. nudus, below). Branchiae are first present 

 from the fourth to sixth segment and continue back to near the end of 

 the body; they are simple, usually lingulate and have fimbriated mar- 

 gins. Interramal cirri are present, or reduced or absent. 



Posterior thoracic neuropodia have thick, modified spines in an 

 anterior series ; the uppermost one is near the aperture of the epithelial 

 glandular organ (pi. 24, fig. 2). The modified spines have been named 

 also "aciculae glochideae" (Kinberg, 1866, p. 251), spears or "spiessig 

 Borsten" (Ehlers, 1897, p. 90), arrow- formed defense setae or "pfeil- 

 formigen Wehrborsten" (Augener, 1923, p. 71), "grosses soies en epieu 

 ou lanceolees" (Fauvel, 1927a, p. 10), "spear-headed chaetae" (Monro, 

 1930, p. 144), "spear-headed spines" (Okuda, 1937, p. 102) and other 

 descriptive names. They are here called spears or spines, depending on 

 their shape. 



Species of this genus have been included in Orbinia (Eisig, 1914, p. 

 273, and Fauvel, 1927a, p. 10). On the other hand they have been 

 considered remote enough to regard them as a distinct family, Phylonidae 

 (St^p-Bowitz, 1948, p. 66). For the present their affinities are believed 

 to be with Orbinia, with which they have many features in common. 



The erratic occurrence of some conspicuous characters is shown in 

 the following chart. 



