262 Papers from the Department of Marine Biology. 



but occurring also on the head and dorsal surfaces of the elytrae, form a notice- 

 able feature of this species. 



Each somite with one or tvto very heavy, long, glassy setae, longer than 

 diameter of body and lying across its dorsal surface. If I understand cor- 

 rectly Augener's description, these are distinct from his "starke dorsale 

 borste," which is shorter than these. I do not find in the latter any minute 

 tubercles and would suggest that perhaps what he saw were particles of 

 foreign matter. 



FAMILY PHYLLODOCID^E. 



Phyllodoce tortugae n. sp. 



Body of type 120 mm. long, of more than 200 somites. Prostomium 

 1.5 mm. in diameter, rather longer than broad (plate 2, fig. 4). Anterior 

 and lateral margins of prostomium rounded, but posterior half of lateral mar- 

 gin nearly straight. Posterior margin deeply incised, and a nuchal papilla 

 projects into this incision. Four subequal tentacles having rounded ends, 

 their length not more than one-fourth that of head. Eyes one pair, large, 

 black. 



The ceratophores of all tentacular cirri are prominent, those of the dorsal 

 ones on somite 2 being the longest. The terminal joint of the first cirrus and 

 the ventral one of the second pair are very similar in form and size, while the 

 dorsal one on somite 2 is the longest, reaching to the ninth somite; cirrus of 

 third somite intermediate in length between the other two. 



The partially protuded proboscis bears on either side a dense arrangement 

 of disk-like papillae, a median dorsal and ventral region being free from them. 



The greatest width of the body, about 3 mm., was reached at somite 18. 

 The anal cirri were much distorted in the type. On a cotype which was regen- 

 erating the posterior end, there was a single anal cirrus similar in form to the 

 tentacular cirri, but much smaller. 



Notocirri of anterior region obovate and inconspicuous in presei^ved material, 

 standing well out from surface of body ; they are larger and more conspicuous 

 toward the middle of the body, and decidedly overlap one another, though at 

 no time do they cover any very large part of the surface. 



The parapodia (plate 2, fig. 5, of the tenth) with a bifid anterior lip, the 

 posterior lip shorter and rounded (shown in dotted line in figure). A single 

 acicula extends through the middle of the parapodium, the latter bearing on 

 the end a row of about 10 compound setse. The notocirrus is carried on a very 

 stout ceratophore. The neurocirrus is on the postero-ventral face of the 

 parapodium, its lower margin broadly rounded, bending up to form an acute 

 angle with the straight upper margin. Later parapodia are similar to this in 

 every detail, with the possible exception of a slight increase in the size of the 

 notocirrus. 



Seta from tenth parapodium (plate 2, fig. 6) slender with the apex of the 

 basal joint covered with spines on its convex surface; terminal joint long, 

 slender, fine-pointed, with row of minute teeth along the concave surface. 

 The setse of later somites resemble these in form, but the basal joint becomes 

 longer, causing the seta to protrude considerably beyond the parapodium. 



Type and cotype in American Museum of Natural History. 



The type was collected at Loggerhead Key in the Dry Tortugas in 1914. The 

 cotype was obtained by dredging about 10 miles south of Loggerhead in 1915. 



