THE POLYCHAETOUS ANNELIDS OF PORTO RICO. 
By AARON L. TREADWELL, 
Professor of Biology , Vassar College. 
The material here described was collected by the expedition sent to Porto Rico 
in the winter of 1898-99, by Hon. George M. Bowers, United States Commissioner 
of Fish and Fisheries. The collection included 85 species of Polychsetes, of which 32, 
so far as 1 could determine, are new. All observations were made on preserved 
material. Where no other preserving fluid is indicated in descriptions of color, etc., 
it will be understood that the specimen was in alcohol. If formalin was used, that 
fact is noted in the description. 
For assistance in procuring literature I am indebted to Dr. H. M. Smith, of the 
United States Commission of Fish and Fisheries, Prof. H. C. Bumpus, of Brown 
University, and Prof. H. P. Johnson, of the University of California. 
All the figures in the text were drawn by the author. 
Family SYLLIDfit. 
SYLLIS Sav. 
Syllis spongiphila Verrill. 
Syllis spongiphila Verrill, Trans. Conn. Acad., vol. 4, pi. 24, figs. 10, 10a, 1881: Kept. U. S. F. C. for 1888, pi. 42, figs. 183, 183a; 
Proc. IT. S. Nat. Mns. 1885, p. 435. 
Professor Verrill describes the color as yellowish white. He does not say if that is the case in the 
living animal. Most of these agree with his description, but in some the anterior portion of the body 
was colored a dark brown by two rather broad brown bands in each seg- 
ment. In the intersegmental constrictions is a narrower band, more 
sharply defined and denser in color. The eyes are farther removed from 
the base of the middle antenna in these than in those figured by Verrill 
and the terminal joint of the seta has more numerous teeth. 
Collected from Boqueron Bay, station 6065, Arroyo, Puerto Real, on 
corals at Mayaguez. 
Syllis eomplanata, n. sp. 
Body very much flattened, with row of dark-brown spots around pos- 
terior edge of head and across posterior portion of each segment. Similar 
spots scattered irregularly over rest of body. Tentacles and all cirri articu- 
lated, with row of pigment granules around each annulus. Median ten- 
tacle longer than lateral, about four times as long as head. Two tentacular 
cirri, dorsal one rather longer than median tentacle, ventral one shorter. 
Palps thick at base, tapering to rounded apex. Eyes four, anterior pair 
the larger. Arrangement of pigment such as to give the appearance of a 
deep cleft on posterior margin of head. (Fig. 1.) Parapodium uniramous, 
with several stout aciculae. Setae few, compound, with long terminal articles; latter with stout subter- 
minal tooth and row of smaller teeth behind it. No tooth in pharynx. The specimen, from Ponce, 
was not complete; about 150 segments present. Length, 44 mm.; width, 2 mm. 
Fig. 1. 
Head of S. complcmata 
x3G. Right paired antenna 
removed to show the palp. 
183 
