PABITS DERODERUS. 457 



Tentacular region greatly elongated into a muscular cylindrical body, or 

 proboscis, at the distal end of which the mouth opens, the elongate body bearing 

 a ring of tentacles distally as well as numerous filiform tentacles over remain- 

 ing part of surface. 



No paleae present. 



Three pairs of thick, distally pointed, branchiae. 



Parapodia of thoracic region each consisting of a long setigerous notopodium 

 and, excepting the first three pairs, of a short, compressed uncinigcrous torus, or 

 neuropodium. Abdominal parapodia consisting of an uncinigerous torus, 

 with, above this, a small glabrous notopodial process and a short tubercle, or 

 cirrus. 



Notopodial setae with tips entire, slenderly acute; shaft narrowly bilim- 

 bate. Uncini pectinate along the free edge as in related genera, the teeth in 

 transverse rows. 



Genotype. — P obits deroderus, sp. nov. 



Characterized by the greatly prolonged tentacular region and the presence 

 of fifteen setigerous somites. 



Pabits deroderus, sp. nov.'^ 

 Plate 77, fig. 5, 6. 



The body is yellowish. 



The thorax narrows gradually from the anterior end to the abdomen; it 

 is evenly convex above, and ventrally below the level of the uncinigerous tori 

 is flattened. Only the anterior end of the abdomen is present. The length 

 from the caudal end of the thorax to the anterior end of the body is about 21 mm., 

 of which the region in front of the first setigerous somite composes nearly 

 8 nrni. The greatest width of the thorax is 3.2 mm. 



At the anterior end of the tentaculiferous region there is the transversely 

 elongate mouth, bordering which above and below is a thick transverse ridge or 

 fold, the distal and inner surfaces of which are minutely papillose and the ectal 

 one more coarsely tubercular. At the ends of the mouth, between the ends of 

 these folds and proximally continuous with them, is a smaller lobe or large papilla. 



The cylindrical tentacuhferous region, or probosciform organ, is 6 mm. long, 

 with a diameter at the distal end of 3 mm., the diameter proximally being a 



1 Sripds long, and Seprj, neck. 



