1906.] NATURAL SCIENCES OF PHILADELPHIA. 247 



preanal segments have two tubercles on each side, one above the other, 

 in the position of the tori, but without setse or uncini. 



In the type the pygidium is very short — less than the two preanal 

 segments — and is terminated squarely by a simple slightly convex 

 plate of broadly elliptical outline. Another specimen has the pygidium 

 more extended and nearly twice as long (on the dorsal side) as the two 

 preceding segments, and the terminal plate is oblique at about 45°. 

 In both specimens the plate is margined by a just evident fold, con- 

 tinuous except on the median ventral region. Just anterior to this 

 margin dorsally is the anus. 



The color is well preserved at the anterior end in a sharply con- 

 trasted pattern of reddish brown and white. On the head the former 

 color occurs as follows : over the entire frontal surface, a half-ring on 

 the dorsum of the posterior end of the prostomium, and a broad ring 

 which occupies most of the peristomium and which is much more 

 deeply colored dorsal to the longitudinal furrow than below it. The 

 white areas are a broad band occupying the sides and dorsum of the 

 prostomium above the mouth, ahd a very narrow ring on the anterior 

 end of the peristomium. On several succeeding segments the arrange- 

 ment is in a narrow anterior red ring, then a white ring occupying most 

 of the glandular zone, and succeeding this an extensive red area 

 occupying all of the rest of the segment. These colors are best devel- 

 oped on the dorsum, and gradually fade until by about somite VII 

 only a nearly uniform dull yellow prevails. The glandular areas are, 

 however, always whiter and more opaque than the remainder of the 

 segment. 



The peristomium and two preanal somites are achsetous, II to V 

 bear small tufts of dorsal capillary bristles, and immediately below 

 them two stout straight spines. Remaining somites have dorsal setse 

 tufts, and below them ventral series of crochets occupying from one- 

 eighth to one-sixth of the circumference of the segment. 



The anterior spines (fig. 40) are deep yellow, with opaque fibrous 

 centres and straight blunt ends. In each tuft the setse number from 

 fourteen to twenty in two ranks. On the proximal part of the exposed 

 portion is a rather wide wing, obliquely striated and often frayed and 

 fringed on the free margin. Just below this the shaft is usually con- 

 stricted, and beyond it tapers to a capillary tip which is short on the 

 anterior and very long and dehcate on the posterior segments, but 

 always, so far as determined, quite devoid of hairs or awns. 



Crochets are always few in number, never more than nine to fourteen 

 occurring in each torus. They (fig. 41) are similar on all segments and 



