NO. 3 HARTMAN : ORBINIIDAE, APISTOBRANCHIDAE, PARAONIDAE 267 



Distribution. — Phylo ornatus occurs on both sides of temperate 

 United States and western Mexico, especially in mud flats in littoral 

 zones. It is recorded from New England south to Florida and in the 

 Gulf of Mexico; also from southern California and Lower California, 

 Mexico. 



Phylo fimbriatus (Moore) 1903 



Aricia fimbriate Moore, 1903, pp. 464-467, pi. 24, figs. 31-35; Okuda, 

 1937, pp. 99-101, figs. 1 to 2 a-g. 



This species is here referred to Phylo Kinberg because posterior 

 thoracic segments have modified spear-headed spines. The prostomium is 

 bluntly conical and much narrower than the smooth peristomium. The 

 thorax consists of 12 anterior and 4 posterior setigerous segments. 

 Branchiae are first present on the fifth and continue on all posterior 

 segments as simple, lingulate, distally pointed processes. In abdominal 

 segments the pair approach middorsally and their bases are united by a 

 transverse epithelial fold. 



Thoracic notopodial and neuropodial postsetal lobes are fringed ; 

 the notopodium has up to 7 to 9 and the neuropodium 12 to 20 lobes at 

 maximum development or in middle thoracic segments ; there are fewer 

 lobes in front of and behind this region. Neuropodia of anterior thoracic 

 segments have palisaded series of many uncini accompanied by long 

 pointed setae. Uncini are slightly curved and distally covered with a 

 hyaline hood ; each has transverse rows of spinelets along the outer 

 curved region. The shortest, bluntest and most curved uncini are in 

 anteriormost rows, and the longest and least curved ones are farthest 

 back. Okuda (1937, p. 100) refers to these various uncini and setae as 

 genuine hooks, subuluncini and canaliculated serrated setae respectively. 



Posterior thoracic parapodia (13 to 16) resemble those in front but 

 are shorter and have modified spines. These form an anteriormost ver- 

 tical row of 5 to 7 dark, lanceolate spines (called acicula by Moore, 

 1903) and are accompanied by more posterior rows of uncini and 

 pointed setae, like those in anterior thoracic neuropodia but fewer in 

 number. 



Interramal cirri are absent. Ventral fringe is sparse; it is first pres- 

 ent as 2 to 4 lobes on segments 14 to 16, then increases to about 9 pairs 

 of lobes through the next 6 to 8 segments (Okuda, 1937, fig. 2c shows 

 9 lobes on a side and a transitional or seventeenth setigerous segment). 

 Furcate setae are present in abdominal notopodia (Moore, 1903, p. 467 

 gives neuropodium, which should perhaps be notopodium). 



Distribution. — Phylo fimbriatus is known only from northern Japan 

 in 20 to 260 fathoms. 



