ART. 15 POLYCHAETOUS ANNELIDS FROM OEIENT TREADWELL 9 



is about one-half as long as the distinct portion of the central area. 

 The slender terminal joint of the median tentacle is about six times 

 as long as the cirrophore, has a slight swelling near the end, and 

 terminates in a filamentous tip. The cirrophores of the lateral ten- 

 tacles are closely crowded ventro-laterally to the median and are about 

 equal to it in size. In the type specimen the terminal joint of the left 

 paired tentacle while more slender than the median, resembles it 

 in form and is nearly as long as it is. That of the right side is 

 smaller and is evidently regenerating. The cirrophores of the tentac- 

 ular cirri are long and slender, their terminal joints shaped like 

 those of the tentacles. The palps are slender and about twice as long 

 as the longest tentacles. On either side of the prostomium is what 

 appears to be two large confluent eyes, the anterior of each pair be- 

 ing the larger. In the center of each is a white spot which repre- 

 sents the lens. It is possible that these " eyes " are really dense 

 accumulations of pigment, obscuring the real eyes which lie in the 

 position indicated by the " lenses." They are dark brown in color, 

 contrasting strongly with the general tint of the prostomium, which 

 in preserved material is light brown with numerous darker patches. 



On the anterior face of each half of the prostomium at the base 

 of the cirrophore of the lateral tentacle is a patch of pigment. The 

 entire dorsal surface of the body is colored like the prostomium, 

 though the parapodia and all cirri are colorless. The brown spots 

 are more or less irregularly arranged but show a tendency to group 

 themselves into two double rows, one near the anterior and one near 

 the posterior margin of the somite, the portion between the members 

 of the double row appearing as a white line. Other markings 

 occur in the form of more or less irregular transverse lines. This 

 color arrangement is most clearly seen toward the posterior end of 

 the body. 



The elytra are translucent and delicate, the first one noticeably 

 smaller than the second. In the type which has its pharynx par- 

 tially protruded, the second elytron covers the prostomium and ex- 

 tends as far as the apex of the cirrophore of the tentacular cirri 

 while the first elytron is crowded ventrally so as to lie on the lateral 

 face of the prostomium. This may be an abnormal arrangement 

 due to the action of the preserving fluids. There are 19 pairs of 

 elytra and in life they must have met over the dorsum, especially 

 toward the middle of the body. Each has a smooth, more or less 

 wavy outline, the surface being smooth except for the dorsalmost 

 quarter of its area where it is thickly studded with spines, each 

 with a trifid apex. A detail of this region is shown in figure 10. 



The parapodia (fig. 11), have pointed setal lobes, into which the 

 aciculae extend, and very small ventral cirri, each globular at the 

 base but with a slender tip. The dorsal cirri are similar in form to 



3023—26 2 



