POLYCHAETOUS ANNELIDS COLLECTED BY THE 

 UNITED STATES FISHERIES STEAMER "ALBATROSS " 

 IN THE WATERS ADJACENT TO THE PHILIPPINE 

 ISLANDS IN 1907-1910. 



By A. L. Treadwell, 

 Of the Department of Zoology, Vassar College, Poughkeepsle, New York. 



INTRODUCTION. 



Some time ago the polychaetous annelid collections made by the 

 United States Bureau of Fisheries- Steamer Albatross in the Philip- 

 pines were sent me for description. As a result of a preliminary 

 study the old species were identified and sent to the United States 

 National Museum some two years ago. Two new species were also 

 described, but since pressure of other duties prevented my continuing 

 the work.the remainder of the collection was turned over to my as- 

 sistant, Miss Ruth Hoagland, whose report follows this. A few 

 old species which I had overlooked are included in her report. These 

 two papers together, then, comprise the report on the polychaetous 

 annelids of this expedition. 



DESCRIPTION OF SPECIES. 



Family SYLLIDAE. 

 Genus AUTOLYTUS Grube. 



AUTOLYTUS TRIANGULIFER Grube. 



Autolytus triangulifer Grube, 1S78, p. 132, pi. 7, fig. 8. 



The polybostricous stage was collected in considerable numbers at 

 San Miguel Harbor, Ticao Island. Grube reported that his speci- 

 mens were incomplete. One specimen in this collection had in the 

 posterior region 31 somites similar in structure, though narrowing 

 very noticeably toward the posterior end. These somites are largely 

 covered by the prominent parapodia. Somites 32, 33, 31, 19, 50, 

 and 51 of the entire body have small parapodia and are covered dor- 

 sally with a brownish pigment, an expansion of the median pigment 

 spots occurring in the anterior somites. Behind somite 11 was a 

 colorless region containing about six somites with very small para- 



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