148 THE ANNELIDA POLYCHAETA. 



is also more lightly distributed over the tentacular cirri and some of the anterior 

 parapodial cirri. 



The type-specimen is complete, excepting the absence of a few somites at 

 the caudal end. Exclusive of the protruded proboscis, it is 22 mm. long. The 

 maximum width, exclusive of the parapodia, is 1.6 mm.; inclusive of parapodia 

 proper, 3.6 mm., and to the tips of the setae, 5.2 mm. The number of somites 

 present is seventy-two. The body is widest near the eighteenth somite, caudad 

 of which across the middle region of the body it narrows gradually and then 

 over the following portion more decidedly, the posterior region becoming 

 slender. The body is compressed dorsoventrally. 



The prostomium protrudes forward conspicuously beyond the eyes and rises 

 dorsad as a high, rounded, subhemispherical, darkened tubercle from which the 

 paired tentacles arise laterally. The tentacles of dorsal pair are broken off; 

 but, judging from the scars, they must have been thick like the ventral ones. 

 Each ventral paired tentacle arises from the ventral surface of the tubercle at 

 the anteroectal corner, farther forward than the corresponding dorsal one; it 

 is subcorneal, distally rounded, and proportionately very thick. The median 

 tentacle is a short, subcorneal, somewhat laterally compressed body standing 

 erect immediately caudad of the tubercle. The prostomium between the eyes 

 from where the median tentacle arises is uniformly depressed, not at all elevated 

 over the axis between the eye centres. The eyes are large, protruding very 

 prominently above the level of the anterior somites, as well as later ad; in each 

 the lens is directed moderately cephalodorsad of directly ectad. The proboscis 

 as protinided is 1 nmi. long and 1.2 mm. thick a Uttle above the base, where 

 widest, being constricted at base and also distad. (Plate 26, fig. 1). 



The labium protrudes moderately ventrad; its anterior margin is gently 

 widely convex on each side, the margins of the two sides meeting at the middle 

 line in a very obtuse angle. There are five pairs of tentacular cirri, of which one 

 pair, as usual, pertain to the first somite, and two pairs to each of the two suc- 

 ceeding somites. The dorsal cirri of the second and third somites are equal 

 or nearly so and much exceed the others. The tentacular cirri of the first 

 somite are but slightly larger than the ventral cirri of the next two; they are 

 conical in form, and a little constricted between middle and tip ; the cirrophore 

 is short and narrower than the style at its widest part. The longer cirri are 

 cylindroconical. (Plate 26, fig. 1, 2). 



The somites are compressed dorsoventrally, the dorsal and ventral arch 

 being equal and low. The anterior somites are very short. The others increase 



