476 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 83 



as long as width of body, provided with dorsal cirri, which extend 

 to edges of special respiratory lobes. Natatory and postnatatory 

 regions characterized by thick, glandular, paired areas above dorsal 

 bases of parapodia. 



Anus provided with two long thick cirri extending posteriorly, 

 each about as long as last five setigerous segments, and two globular 

 dorsal cirri, each slightly wider than half of body width at their 

 point of attachment. 



Setae all composite; falcigerous homogomph notosetae and neuro- 

 setae as in figure 50, A, i. 



Holotype.—V.S.'NM. no. 20204. 



Locality. — Three specimens from Moss Beach, San Mateo County, 

 Calif., collected in tow with electric light between 8 and 9 p. m.. 

 July 1934. 



Remarks. — This species is placed in the series of Nereis (sensu 

 stricto) because of the presence of homogomph notosetae in posterior 

 parapodia. Atokous specimens have not been observed. With re- 

 spect to the structure of its postnatatory parapodia, it lies between 

 N. neoniffripes, new species, and N. eakini, new species. 



NEREIS (CERATONEREIS) TUNICATAE, new species 

 FlGTJEE 51 



Measuretnents. — Length, about 20 mm; width, 1 mm, including 

 parapodia between segments 15-25; number of segments, 68 in one 

 specimen, TO in another. 



Description. — Prostomium relatively small, with region anterior 

 to eyes longer than broad; the posterior third provided with four 

 black eyes disposed in a rectangle, the anterior pair the larger. 



Antennae extending distally beyond palpophores, almost con- 

 tingent at their bases, diverging slightly distally. 



Palpi broader than width of prostomium, thick, touching ven- 

 trally; palpostyles hemispherical. 



Peristomium II/2 times as wide as segment 2, constricted in an- 

 terior third ; a smooth ring except for three shallow grooves laterally 

 and a few short grooves at the oral opening. 



Peristomial cirri short, \X\^ longest less than twice as long as 

 peristomium, annulated in distal half; the shortest as long as 

 peristomium; cirrophores smooth rings, weakly pigmented. 



Paragnaths absent from oral ring; area I with none; II with 

 three tiny cones; III with one minute cone; IV with three small 

 cones in a transverse row. 



Jaws pale amber, translucent, with five teeth. 



Parapodia (fig. 51, «, 5) anteriorly with conspicuous dorsal and 

 ventral lobes, which are equal or subequal (fig. 51, a) ; median para- 



