NO. 3 HARTMAN : ORBINIIDAE, APISTOBRANCHIDAE, PARAONIDAE 259 



fig. 1 ) . A ventral cirrus and interramal cirrus are absent. Thoracic 

 neuropodia have up to 5 or 6 rows of setae in the middle region where 

 best developed ; the rows diminish to 2 or 3 farther forward and back. 

 The anteriormost vertical row has alternating pointed setae (pi. 21, 

 figs. 2, 3) resembling those in front. The outer side of the seta is pro- 

 vided with transverse rows of spinelets. Uncini are slightly curved 

 and distally blunt. When perfect they are distally covered with a close 

 hyaline hood ; most uncini have no hood, perhaps as a result of wear. 

 The convex curved region has 5 to 7 or 8 transverse ridges (pi. 22, 

 figs. 5, 6) or it may be nearly or entirely smooth. 



Furcate setae are first present in notopodia after the disappearance 

 of the ventral fringe. They may number up to 9 in a bundle but diminish 

 to only 2 to 4 or 5 in some fascicles. They are continued back to near 

 the end of the body and have the usual position in the inferior part of 

 the notopodial fascicle. The shaft or stem is nearly cylindrical ; external- 

 ly it is smooth except for 14 to 20 transverse, incomplete rows of short 

 spinelets on the side marking that of the shorter distal tine (pi. 22, figs. 

 7, 8). The rows of spinelets extend about one-third to one-half way 

 around the stem. The core of the stem is penetrated by strong parallel 

 fibrillae. The two distal tines are unequally long; the shorter is slightly 

 the slenderer. Each tine terminates in a flaring tip that is cupped or 

 grooved at its outer side (pi. 22, fig. 7). The inner sides of the tines 

 give rise to a continuous thin flange or membrane traversed lengthwise 

 by 5 to 10 strands continuous with those within the stalk. This mem- 

 brane, when perfect, is pouched (pi. 22, fig. 7) ; when torn or imperfect, 

 there may be only a few of the several fibrils of the membrane, resem- 

 bling long teeth or a diverging spine. It seems likely that a similar condi- 

 tion of wear is illustrated in published accounts of furcate setae for 

 some other species. 



Acicula number 3 to 5 or 6 in a fascicle; they are fully embedded. 

 The pygidium has a series of long, slender filaments attached dorso- 

 lateral^ (pi. 22, fig. 2). 



Some individuals taken in June in central California and in March 

 in southern California are mature; ova are first visible 4 or 5 segments 

 behind the fringed region and continue back to near the end of the body. 

 In these segments the nephridial pore, located on the posterior side of 

 the neuropodial flange, is more conspicuous and tumid than elsewhere. 



Color in life is satiny pale green. In central California the species is 

 associated with Nephtys caecoides Hartman; in southern California it 

 is found in sandy beaches where Euzonus (Thoracophelia) mucronata 

 (Treadwell) occurs. 



