POLYCHAETE WORMS, PART 1 267 



ing posteriorly. Prostomiiini (fig. 68a) bluntly to sharply conical, 

 with posterior median notch (notch is bordered by 2 short trans- 

 lucent areas or nuchal organs), without eyes. Parapodia with pre- 

 setal lobe short, rounded, with digitiform postsetal lobe in anterior 

 region, diminishing in size and length in postbranchial region. With 

 digitiform branchiae formed below the postsetal lobe, beginning on 

 setigers 2-4 as a single lobe, increasing gradually in number of lobes 

 up to about setiger 10, diminishing in number of lobes at about setiger 

 25 and disappearing on about setiger 26 (at setiger 9 in very small 

 specimens, to setiger 32 in large specimens). Branchiae up to 1 to 7 

 lobes, palmately digitiform below the digitiform postsetal lobe (fig. 

 686). Parapodia with vertical fan-shaped tuft of simple limbate 

 pointed setae (hg. 68c) and simple hooded crotchets. Crotchets long 

 winged in anterior region (fig. 68(/), becoming short winged in mid- 

 dle and posterior regions (fig. 6Sg). Setae dark at base, pale distally. 

 Acicula black. Pygidium with two short ventral anal cirri. 



Proboscis with, mandibles delicate, white, calcareous, with long 

 slender basal pieces and flaring distally (fig. 68/). Maxillae i slender, 

 hooked, with short broad maxillary carriers; maxillae ii each with 

 6-8 teeth; maxillae iii and iv each with a single tooth (larger distal 

 fang with minute denticles or frayed edge more proximally, fig. 68^^). 

 Color: u'idescent, flesh or tan; may have white dotted areas forming 

 wide transverse bands; parapodia dark due to black acicula and 

 dark bases of setae; branchiae bright red, with red dorsal and ventral 

 longitudinal blood vessels. 



Biology. — Found at low water in mud. Dredged on bottoms of 

 soft or sticky mud, sandy mud, silty clay and fine sand, mud mixed 

 with gravel, shells, and worm and amphipod tubes. One specimen 

 found in the oceanographic fouling studies in the New England region. 

 Form tubes of mucus mixed with mud and sand. May form mucous 

 tubes m the dishes in the laboratory. Males filled with white sperm 

 masses and females with large orange yolky eggs (about 160-190ju 

 in diameter) found in the Cape Cod Bay region during June, July, 

 and August, as well as numerous very small specimens. Among the 

 specimens collected in Massachusetts Bay by the U.S. Bureau of 

 Fisheries (Location 232, Septcm^ber 24, 1878), fertilized eggs were 

 present among the parapodia in the branchial region. The yolky 

 eggs were being extruded from large pores below the parapodia. 



Material examined. — Numerous specimens from Gulf of St. 

 Lawrence (Gaspe Bay, 3-4 fathoms). New Brunswick (Miramichi 

 estuary), Nova Scotia, Maine (St. Croix River, Red Beach, low water; 

 north end Long Ledge, Sheepscot River, 3 fathoms; Ebenecock Har- 

 bor, Southport Island), Massachusetts (Georges Bank, 32-86 fathoms, 

 Cape Cod Bay, Nantucket Sound, Buzzards Bay, Vineyard Sound), 



569-457—63 18 



