PELAGOBIA VIGUIERI. 123 



of each is conspicuously acuminate distad, with the tip very slender. The cera- 

 tophore considerably thicker than the style at its base and but little longer than 

 thick. The setigerous lobe short, with its setae projecting conspicuously. 



The second somite is typically narrower than the first, but may be equal to 

 it or occasionally may exceed it. It is of the same length as the first. The third 

 somite is always narrower than the first and usually than the second. The 

 length of the somites does not vary much with the marked increase in width 

 in the middle region, but they are shortened toward the narrowed caudal end. 

 The convexity of the somites is but moderate, more marked in the anterior 

 region, and about equal ventrally and dorsally. 



The parapodia are strictly lateral in position. The neuropodia of those 

 of the second somite are short and conical, those of the next somite abruptly 

 longer, while the next few increase in length more gradually until the maximum is 

 reached. In the posterior region they again gradually decrease in length. The 

 neuropodia are cylindroconical and rather long, in the middle region being about 

 four fifths as long as the width of the somite proper. The cirri are longer than 

 the neuropodia and attain to near the end of the setae. On a typical para- 

 podium, as occurring over the greater part of the body, the notocirrus is attached 

 distad of the middle. Its cirrophore is swollen and continuous with the noto- 

 podium, which is separated by a furrow along each side. The style acuminate 

 or subulate, and not attaining fully the ends of the setae. The neurocirrus is 

 attached on the ventral surface almost directly opposite the notocirrus, which 

 it closely resembles in form and size. 



In each parapodium is a single fully developed aciculum; the acute tip of 

 this extends through a slender prolongation at the tip of the neuropodium and 

 projects freely a considerable distance beyond the surface. The setae are all 

 compound. Each has a long, uniform shaft which is wholly smooth, showing 

 no serrations, and ends in a deep, not transversely thickened socket which is 

 asymmetrical. The blade is long, attenuated distad, and acute at the tip; in 

 side view it is seen to be boldly and closely serrate from base to tip. 



Localities. Between the Galapagos Islands and Peru: Sta. 4646 (lat. 

 4° 02' S., long. 89° 16' W.). 300 fms. to surface. Surface temp. 70° F. 8 

 November, 1904. Two broken specimens. 



Between the Galapagos Islands and Peru: Sta. 4649 (lat. 5° 17' S., long. 

 85° 20' W.). 300 fms. to surface. Surface temp. 70° F. 10 November, 1904. 

 One broken specimen. 



Off Peru: Sta. 4646 (lat. 11° 30' S., long. 87° 19' W.). 300 fms. to surface. 



