1902.] NATURAL SCIENCES OF PHILADELPHIA. 267 



Lagisca multisetosa sp. nov. 



Like other species of Lagisca this is slender, with llie widest part 

 of the body far forward at somite VI, behind which it diminishes 

 gently, while the anterior end is broadly rounded. The type speci- 

 men consists of the twenty anterior somites and measures 11 mm. 

 in length, 3.2 mm. in width of body at VI, 5.3 mm. to tips of 

 feel, and 8 mm. to tips of the setse at the same place. It will be 

 obseryed that the parapodia are here relatively short. 



The head is three-fourths as long as wide, Avith a gently couyex 

 posterior border, lateral margins prominently bulged at the middle, 

 and the anterior fissure deep, with a narrow furrow continuing it 

 back to about the middle of the head. The two halves of the 

 head are produced forward around the base of the middle tentacle, 

 and the prominent peaks in which their outer sides end are widely 

 separated from the latter. The frontal ridge is strong and high. 



The posterior eyes are situated close to the posterior margin of 

 the head and separated by four times their diameter. They are 

 black, circular and look upward and slightly outward. The ante- 

 rior eyes are of the same shape and color, but about twice the size 

 of the posterior. They are situated relatively far back, not more 

 than their own diameter in advance of the posterior pair, but on 

 the ventro-lateral surface, though they may be seen through the 

 tissue of the head from above. 



Of the cephalic appendages the median tentacle is absent, but its 

 deep chocolate-colored base remains. The lateral tentacles have a 

 length about equal to the width of the head, and are slender and 

 tapering, the distal half being filiform. They arise entirely below 

 the level of the median tentacle and their bases aie almost in con- 

 tact in the median line. The palps are about two and one-half 

 times the length of the lateral tentacles, taper to a very acute tip, 

 and bear two dorsal lines of very small cilia, with a few of the 

 same kind scattered over the surface. The dorsal tentacular cirrus 

 about equals the palp in length; the ventral is slightly shorter. 

 Both taper from the base to a very slight subterminal enlargement 

 bearing a short terminal filament. Short truncate cilia are spar- 

 ingly scattered over the surface, being rather more numerous just 

 below the subterminal enlargement. 



Although the setae are long the parapodia themselves are short, 

 the tenth, for example, being somew^hat less than one-half the width 



