1903.] NATURAL SCIENCES OF PHILADELPHIA. 431 



the end; the dorsal cirrus is H times the length of the notopodium 

 and the ventral shghtly longer than the neuropodium. Posteriorly the 

 notopodium increases relatively in size, giving the entire parapodium 

 an oblique aspect, at the same time becoming much more vascular and 

 contractile, which greatly affects the relative proportion of parts in 

 neighboring parapodia. Otherwise they undergo little alteration. 



The setse are all compound and three forms occur. The notopodials 

 are all similar, with slender, strongly and closely camerated shafts, 

 symmetrical sockets and long, straight, slender, tapering and strongly 

 fringed blades. In addition to the setae of the notopodial kind which 

 are the most numerous dorsal to the aciculum of the neuropodium, the 

 latter bears two other forms of compound set*. In the ventral part 

 of the foot are some rather stouter ones, in which the shafts are cam- 

 erated and the sockets oblique, the fringed blades much shorter, broader, 

 hooked and guarded at the apex. Two or occasionally 3 much stouter 

 deep yellow setse project stiffly from a point just dorsad of the acicu- 

 lum ; the camerated interior of the shaft is marked by a central line, 

 perhaps due to perforations in the septa, its end bears a shallow 

 oblique socket, and the very short blade, which is very seldom present, 

 is strongly hooked, striated, guarded and furnished with a marginal 

 fringe of long hairs. 



Maxillae brown, broad, not especially acute, abruptly oblique at 

 end, each with 8-9 teeth in addition to the terminal fang, from which 

 they are separated by a short interval. Paragnatha almost obsolete; 

 maxillary ring: I, wanting; II. 2-4; III, 1; IV, 2; a very minute one 

 on each side between III and IV; basal ring represented by three small 

 teeth arranged in an arc on the ventral side; all are small, low conical 

 and brown. 



One specimen, type, north of the Aleutian Islands, 3,785, 270 fms. 

 Nereis pelagica Linn. 



Sagami Bay, 3,700, 63 fms.; Totomi Sea, 3.729, 34 fms. 



NEPHTHYID^. 

 Nephthys brachycephala sp. nov. 



None of the specimens is complete, the type and most perfect one 

 having 60 segments and a length of 64 mm., the maximum breadth 

 between the tips of the parapodia being 4 mm. at X. Body relatively 

 slender, not depressed, anteriorly nearly round, but venter somewhat 

 flattened; posteriorly nearly quadrate. 



Prostomium very short, twice as wide as long, deeply sunken (about 

 Y of its length) in peristomium. roughly oblong, with anterior angles 

 slightly truncated, lateral margins slightly convex, anterior gently 



