4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 9I 



and soft. I am uncertain whether the denser appearance at the elytro- 

 phore is due to a thickening of ,the tissue or to a greater accumulation 

 of sand grains at that point. As far as about somite 25' the dorsal 

 exposed portion of the body wall seems to be thin and delicate. Behind 

 this point the body narrows, the sand grains are larger, and the elytra 

 cover more of the surface. The last somites present in the fragments 

 are completely covered. Beyond about somite 25 each has on its 

 dorsal surface three transversely arranged bunches of sand grains, 

 successive somites thus showing three longitudinal rows of sand piles. 

 It is possible that these represent three rows of rudimentary gills, 

 l)ut I was unable to discover any trace of gills in them. 



The dorsal appearance of the first parapodium has been given 

 above. On the ventral surface there is a short cirrus near the end 

 of the neuropodium. The setae of this parapodium are of varying 

 sizes but are all essentially the same in structure in that they carry 

 two rows of toothed plates, giving the setae a double saw-tooth 

 effect. The second parapodium carries a whorl of very fine setae, 

 which have minute lateral plates forming spines as in the first. In 

 the neuropodium are a few much larger setae, which are smooth 

 throughout the greater part of their length but toward the end acquire 

 lateral plates. Toward their ends, they widen and then narrow again, 

 forming what one would expect to be a narrow lanceolate apex, but 

 this suddenly ends and forms the basis for a slender and much curved 

 terminal joint (fig. 8). The second parapodium has the form of a 

 truncated cone, is very much annulated on its surface, and has a long 

 cirrus at its apex, together with a bunch of smaller cirri. Except 

 for the absence of the long terminal cirrus, the third parapodium 

 is much like the second. The dorsal setae are like those in the noto- 

 podium of the second parapodium, whereas ventral ones are compound 

 but without the lateral teeth. These are continued in later somites, 

 but the terminal joint may be very short. In the third parajwdia are 

 also very slender colorless compound setae having long and slender 

 terminal joints. 



Type. — U.S.N.M. no. 20032. Specimens were collected at sta- 

 tion 100, at latitude i8°38'45" N., longitude 64°52'45" W. — latitude 

 i8°4o'i5" N., longitude 64°5o'i5" W., in 15 fathoms (type speci- 

 men) ; and at station 28, latitude i8°3i'4o" N., longitude 66° 12' W. — 

 latitude i8°32' N., longitude 66°i4'45" W., in 40 fathoms. 



