No. 40 



NORTH-AMERICAN ECHIURIDS. 



171 



Color uniform gray or grayish-yellow, shading into a deep 

 orange on the interior of the proboscis. Entire surface of the 

 body rough from being covered with small blunt papillae, which 

 are unequal in size. The larger ones are more globular and are 

 quite regularly arranged in transverse rows in which the indi- 

 vidual papillae are so close together that they touch one another. 

 There are twenty-two or twenty-three of these rows, and be- 

 tween them are scattered the smaller papillae, which are more 

 conical in shape and seldom show any arrangement in rows. 



Both kinds of papillae are more sharply defined and nearer 

 together toward the ends of the body. There is also usually 

 a bunching of the papillae around the anterior setae where 

 they are larger than elsewhere on the body. 



There is a pair of large, shining yellow, hooked setae, one 

 on either side of the ventral mid-line, 16-20 mm. behind the 

 base of the proboscis. These setae are about 20 mm. long and 

 curve toward the posterior end of the body. They are retrac- 

 tile and can be almost wholly withdrawn into the body cavity. 

 The posterior end of the body is surrounded by two rows of 

 yellow setae, somewhat shorter than the anterior pair and per- 

 fectly straight. They also are retractile, and in most preserved 

 specimens are withdrawn into the body cavity. In the animal 

 shown in Fig. 4, however, they were extended to their full 

 length. The rows are quite near together (3-5 mm.) and 

 not more than 4 mm. from the anus, which is central and termi- 

 nal. These posterior setae incline backward and assist the ani- 

 mal in moving about. The anterior row is made up of eight 

 or nine setae, the posterior one of seven or eight. ^ 



Reserve setae are present for both rows and for the ventral 

 pair. The setae alternate in the two rows, but neither row is 

 entire, a space being left on the ventral mid-line. 



In the posterior row this space corresponds to the omission 

 of one seta, in the anterior row to the omission of three. 



There is a papilla around the base of each seta, much larger 

 than those on the body. The spaces between these basal papil- 



^ The fact that these different numbers may be found in individuals otherwise 

 exactly alike is still further evidence that Reinhardt's species, forcipatus, is not 

 well grounded. 



