224 THE ANNELIDA POLYCHAETA. 



in the more ventral ones the ribs extend less and less toward the base. In the 

 most caudal parapodia, as the ultimate and penult, only the ribbed setae are 

 found; but these appear no longer compound, but rather as simple blades ribbed 

 over most of the expanded portion. (Plate 31, fig. 9). 



Dissection shows the paragnatha to be very small and to be closely ranged 

 in Unes in areas III and IV. The maxillae are colorless and transparent except 

 distally where tinged with brown. They are well curved in a direction against 

 the flat surface. Each is relatively narrow distally, having a subacute point 

 below which there are, in the single specimen dissected, eight rather large and 

 oblique teeth. (Plate 31, fig. 4). 



Epitokous Female. 



The general color is dull yellow as in the male. The purple spots on each 

 somite are often united by fine transverse Unes of the same color. 



The body is moderately convexly arched above and about equally arched 

 below. It is widest near the middle of the anterior division from where it narrows 

 conspicuously forwards. The posterior half of the posterior division narrows 

 strongly caudad to an acute angle. The total length of the maximum specimen 

 is near 27 mm., with a maximum width, exclusive of parapodia, of 3 mm. In the 

 anterior division there are typically twenty-three setigerous somites and in the 

 posterior division from sixty to seventy, which, with the peristomium, gives a 

 total of from eighty-four to ninety. 



The main part of the prostomium, occupied by the eyes, is quadrangular, 

 the region in front of the eyes being in outline in the form of a low triangle, with 

 the apex broadly rounded and much shorter than in the male. This apical 

 region is more transparent, as in the male, and is similarly flattened dorsoventrally. 

 On the ventral surface of this anterior portion are borne the two tentacles. 

 These are conically tapered from the base, where they are contiguous, to an 

 acute point. When extended directly caudad, as seems to be usual in the pre- 

 served specimens, they reach beyond the anterior border of the mouth and 

 nearly to the tips of the palpi, being actually and relatively much larger than in 

 the male. The palpi are attached on the ventral surface in front of the mouth 

 and between the positions ot the anterior eyes. The distal article of each is 

 short and rounded, but little longer than thick. The proximal article is much 

 thicker. The four eyes are large, though the posteriors are decidedly smaller 

 than in the male. On each side the posterior eye is directly caudad of the ante- 



