Handbook of Paleontology 147 



of Great Britain and Europe. It can be traced by the 

 castings at the mouths of the burrows which are such a 

 marked feature of tidal mud flats or of sands with an 

 underlying layer containing vegetable detritus. This 

 worm is five to ten inches long and of a brownish green 

 color, with 12 to 13 pairs of branched red gills. In some 

 areas, particularly where sheltered as in estuaries, it 

 occurs in immense numbers, varying with the food sup- 

 ply. The Ribbon Worm {Meckelia ingens) is common 

 on both muddy and sandy beaches living beneath the 

 ground near low-water mark, from South Carolina to 

 Cape Cod. While a good swimmer, this is a burrowing 

 form and, though soft, penetrates the sand with great 

 rapidity. It is yellowish or flesh color and when full 

 grown attains a length sometimes of 12 to 13 feet when 

 fully stretched, though when contracted, even the largest 

 measure no more, than five feet. The Pink Ribbon Worm, 

 (M. rosea) is much smaller, never more than ten inches 

 long and a quarter of an inch wide. It lives in sand near 

 low- water mark. It is dull red or flesh colored, but the 

 body is slime-covered and the sand adheres tenaciously. 

 There is also a dark flesh colored or purplish worm (Tet- 

 rastemmea arenicola) living in sand at low- water mark. 

 This form is slender, cylindrical and four to five inches 

 long when extended. The Four- Jawed Worm {Eugly- 

 cera americana) is a stout, active worm, one foot long 

 and a quarter of an inch wide, which has the appearance 

 of a reddish iridescent earthworm. It is common in our 

 beaches between tide limits. The so-called Blood-Spot 

 {Poly cirrus eximius) is another worm that lives on our 

 sandy beaches immediately below low-water mark. It is 

 about four inches long and the forward half of the body 

 is blood-red. The blood red tentacles that surround the 



