chamberlin: pacific coast polychaeta. 259 



ten teeth and at anterior end a large curved fang well separated from teeth 

 by a smooth edge. Right maxilla II much shorter, ending posteriorly at 

 anterior end of dental series of I; toothed all the way to anterior fang, there 

 being seven rather blunt teeth excepting the one adjacent to the fang which is 

 much smaller and more acute than the others. The left maxilla II bears six 

 teeth inclusive of the terminal fang, the tooth at the base of which is much 

 smaller than the others, the third tooth from the proximal end largest. Right 

 maxilla III with four teeth, the fang more widely separated because of the 

 obliteration, or nearly so, of the minor tooth adjacent to it in the left plate. 

 Right maxilla IV with four small even teeth. Plate V reduced to a small 

 hook as usual. 



Prostomium broadly ovate, more rounded anteriorly than represented for 

 A. aUenuata; clearly longer than the first two somites together. Eyes in a 

 transverse row across base as usual; the median ones more sharply defined 

 than the lateral ones but much smaller, the reverse of the relation in aUenuata. 



First achaetous segment much longer than the second. 



Posterior lobe of parapodia large, projecting caudoectad and also curving 

 more or less dorsad, distally bluntly rounded, always much exceeded by the 

 setae. Setae in middle region of body mostly from five to eight in number 

 in each parapodium. Upper ones with long shafts, strongly bent at beginning 

 of limbate portion, the distal curve gentle. Number of segments in type 

 three hundred and fourteen. 



Length, 95 mm.; greatest width, 2.2 mm. 

 Locality. — CaHf . : Crescent City (A. Agassiz). 

 Tijpe.— M. C. Z. 211. 



19. BiBORiN ECBOLA Chamberlin. 



Pomona College journ. zool. ent., 1919, 11, p. 13. 



One specimen taken between tide marks on San Miguel Island 

 by W. G. W. Harford. It is a larger specimen than the type, being 

 135 mm. long and having a maximum diameter of 2.5 mm. though 

 composed of fewer somites, — about two hundred and forty-five as 

 against two hundred and seventy-seven. It is brown in color with 

 superficial iridescence. The prostomium is less pointed than in the 

 type, anteriorly more broadly rounded, though this seems in part due 

 to shrinkage from preservation. The posterior process of parapodium 

 is longer in general proportionately to the basal part of parapodium 

 and to the setae. 



