NEMERTEANS 



189 



chestnut, or slaty, with a tinge of green in reflected light, or of plumbago 

 or bluish when seen in shadow. Sometimes a reddish tinge is given to 

 the brown, and there is usually a soft, velvety sheen. Head has a rosy 

 or chestnut tinge beneath the brown. Tip of tail very pale in color. 



Throughout the whole body is usually found a series of transverse 

 and longitudinal yellowish markings on dorsal surface. The trans- 

 verse markings are the more conspicuous and consist of a series of 

 lemon yellow rings. The more anterior of these commonly encircle 

 the whole body, while farther back they appear on dorsal surface only. 

 They are all much widened in the median line, and in some specimens 

 appear to consist only of a series of diamond-shaped median markings. 

 More commonly, however, each marking continues laterally as a fine 

 line which completely encircles the body, although many are inter- 

 rupted on the ventral surface. In the posterior half of the intestinal 

 region these markings do not usually appear on the ventral surface. 

 In some specimens the markings are very much obscured and occa- 

 sionally are almost completely wanting. The first transverse marking 

 occurs at the posterior end of the cephalic furrows, and this is usually 

 much larger and more conspicuous than any of the others (p1. xvii, 

 fig. 5) although it does not extend to the ventral surface. On a worm 

 of 10-20 cm. in length there are usually sixty to one hundred or more 

 of these transverse rings. 



The dorsal surface is corrugated with longitudinal flutings, except 

 when the animal is fully extended. These flutings are accentuated by 

 very fine, halr-like longitudinal lines of ochre or orange color which 

 extend throughout most of the dorsal surface. They are not only very 

 fine, but are much interrupted and irregular, usually wavy, and often 

 consist of rows of elongated dots of color. On the head the lines are 

 much interrupted and consist mainly of rows of very minute dots. 

 On the ventral surface they are entirely wanting throughout the body. 

 On the dorsal surface there are commonly about seven to fifteen or 

 more of the fine lines, of which the one in the median dorsal line is 

 more distinct than the others, and connects the transverse, diamond- 

 shaped, pale yellow markings described above. On each side of the 

 median line the lines are sometimes arranged rather symmetrically, but 

 are sometimes almost entirely lacking. This is often the case in the 

 posterior half of the body. In many specimens the lines are seen only 

 when very carefully examined, and in some others appear to be en- 

 tirely lacking. Sometimes they are wanting anteriorly to the third or 

 fourth transverse yellow marking. The transverse markings are of a 

 much paler yellow than are the longitudinal lines. 



