A NEW MARINE ANNELID FROM CHILE. 



By A. L. Treadwell, 

 0( the Department of Zoology, Vassar College, Poughkeepsie, Neto York 



Among other material collected by Dr. F. Felippone, at Punta 

 Arenas, Chile, during the past year was found a single, incomplete 

 annelid, which was submitted to me for examination by the United 

 States National Museum. I have been unable to find this described 

 in any literature at my disposal and am recording it here as a new 

 species, though because of the imperfect condition of the specimen 

 the specific description must be incomplete. It has been included 

 under Lagisca, because of the form of the prostomium, the fact that 

 the neuropodial setae are smaller than the notopodial and have 

 transverse denticulations, and on the assumption that only a small 

 portion of the posterior end is missing. 



LAGISCA CRASSA, new species. 



The prostomium (fig. 1) is much broader than long, and is divided 

 anteriorly by a deep V-shaped incision which extends half way of the 

 length of the prostomium. From its posterior angle a slight dorsal 

 depression continues posteriorly for the remainder of the prosto- 

 mium. The result of this structure is that the prostomium is 

 divided into halves, each roughly ovate in outline with its outer 

 margin decidedly rounded toward its posterior end. From the 

 point of greatest width the lateral margins slope gradually toward 

 the anterior end where they meet with the inner margins which 

 form the edges of the V. These two margins meet at a blunt angle 

 but do not form a decided " peak." The eyes are all of approxi- 

 mately the same size, the posterior pair situated near the dorsal 

 mid-line of the corresponding half of the prostomium a little 

 posterior to its center. The anterior eyes are a very little farther 

 apart than the posterior, and situated near the anterior margins. 



The median tentacle has a stout cirrophore which completely fills 

 the above-mentioned V in the prostomium, and is about as long as 

 the prostomium. The terminal joint is about as long as the cirro- 



NO 2'^36— PROCEEDINGS U. S. NATIONAL MUSEUM, VOL. 65, ART. 23. 



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