A NEW POLYCHAETOUS ANNELID OF THE GENUS 

 NEREIS FROM BRAZIL. 



Vassar College, Puughkeepsie, New York. 



The following description is of a Nereis collected at Santos, Brazil, 

 in July, 1913. It was transmitted to the United States National 

 Museum by the director of the Museu Paulista, Sao Paulo, Brazil, 

 and by them sent me for identification. 



NEREIS BREVICIRRATA, new species. 



The collection contained two entire specimens of adult females 

 with eggs. The length was about 30 mm. with a peristomial width of 

 B mm. The only trace of color in the alcoholic material was a brownish 

 tint, forming a fairly uniform shading on the anterior region as 

 far back as the fifth somite. Behind this the color is limited to a 

 darker brown median band, which at somite 12 narrows and becomes 

 very indistinct for the remainder of the body. In the preserved 

 material the dorsal blood vessel shows as a prominent narrow stripe. 



The prostomium (fig. 1) is very slightly rounded anteriorly, the 

 width at the anterior margin being practically equal to that just in 

 front of the anterior eyes. A median longitudinal dorsal groove 

 extends from the anterior margin to the level of the anterior pair 

 of eyes. The entire lateral margin of the prostomium is fused with 

 the inner face of the palp, though as far back as the anterior pair 

 of eyes a faint groove marks the line of fusion. Behind this point 

 the fusion is complete. The tentacles are separated at their bases by 

 a distance equal to their diameter, and are relatively small, conical, 

 with acute tips. The palps are very thick and fleshy, as broad as the 

 peristomium, with a very small terminal joint. Toward the end a 

 transverse groove simulates an articulation. 



The tentacular cirri are small, most of them not reaching the 

 apex of the palp. The posterior dorsal one is the most slender, and 

 extended in one specimen as far as the posterior border of somite 2, 

 while in the other it was much shorter. This is evidently a varia- 

 tion due to the preservation. The other cirri are not more than a 

 third as long as this, conical, with acute tips (fig. 1). 



Tlie peristomium is longer than the prostomium, and shorter than 

 the second and third somites combined, though longer than the sec- 

 ond. Toward the posterior end of the body there is a gradual de- 

 crease in the diameter. There is one pair of long, slender anal cirri. 



Proceedings U. S. National Museum. Vol. 6S-No. 2347. 



467 



