258 bulletin: museum of comparative zoology. 



ones much larger than the posterior; most not showing any distinct segmenta- 

 tion, but some of the anterior ones more or less divided into a long basal 

 segment and usually three smaller distal ones. Neurocirri all thick, short, 

 subconioal, and much exceeded by the setae. Shaft of composite setae strongly 

 enlarged distally. Appendage bidentate, the upper tooth erect, the smaller 

 lower one forming a very obtuse angle with it, and nearly at right angles to the 

 axis of the appendage; guard narrow; length of appendage less than once 

 and a half the diameter of the e.xpo^ed portion of shaft. General color light 

 brown, branchiae paler; no distinct markings. Anal cirri long, slenderly 

 tapered. Total number of segments one hundred and eighty-one. 



Length, 140 mm.; greatest width, 7 mm. 

 Locality. — Calif.: Mendocino (A. Agassiz). 

 Type.— M. C. Z. 120. Paratypc— 121. 



LUMBRINEREIDAE. 



17. LuMBRiNEREiszoxATA Johnson. 



Proc. Boston soc. nat. hist., 1901, 29, p. 408, pi. 9, fig. 93-100. 



Several small specimens referred to this species differ from typical 

 larger specimens in wholly lacking brown annulations, being uniform 

 yellow of a slight ferruginous tinge. The crochets and setae are 

 relatively longer than in the type but agree in distribution. One 

 immature specimen from Crescent City and several from Mendocino 

 (A. Agassiz). 



18. Arabella munda, sp. nov. 



The general color light reddish brown with a darker longitudinal stripe, 

 which is not sharply limited, along each side of the dorsum just above the 

 parapodia. Body moderately narrowed from the middle cephalad but much 

 more strongly so caudad, the posterior end being pointed. 



This species in some features much suggests A. atteniuita Treadwell but 

 appears obviously distinct in the structure of the maxillae. These are black 

 throughout. Right maxilla I with seven (six) large teeth, the fang at distal 

 end bent mesad almost at right angle. Maxillae II strongly asymmetrical as 

 in A. mimeiica Chamberlin. The right plate long and extending proximad 

 down the mesal side of the dental line of I to base of latter; bearing nine or 



