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FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



and below from Cape Cod to northern Florida and 

 on the Gulf coast at least as far west as Louisiana. 



Order 2 HETERONEMERTEA 



Family LINEIDAE 



Zygeupolia rubens Goe, 1905, 1940, 1943 



Valencinia rubens Coe, 1895; Zygeupolia Hloralis 

 Thompson, 1900. 



The worms of this species may be identified by 

 the red or rosy color and sharply pointed head 

 which is devoid of ocelli or longitudinal grooves, 

 as well as by the long caudal cirrus. Length 40 to 

 80 mm. when mature; width 2 to 5 mm. 



Found in sand or beneath stones in the inter- 

 tidal zone and below from southern New England 

 to northern Florida and on the Gulf coast westward 

 to Copano Bay, Tex.; also from Monterey Bay, 

 Calif., to Mexico. 



Lineus socialis Verrill, 1892; Coe, 1943 



Nemerles socialis Leidy, 1855. 



Recognized by the very slender body with a 

 row of two to eight small ocelli on each side of 

 head and by the tendency of the worms to coil in 

 spiral when disturbed. Length when mature 30 

 to 150 mm., width 1 to 3 mm. Color variable, 

 often pale olive green, greenish brown, or reddish 

 brown ; frontal margin and lateral borders of head 

 whitish; brain region deep red; body sometimes 

 encircled with 6 to 20 or more narrow and 

 inconspciuous rings of lighter color. 



Lives beneath stones and among mussels and 

 other growths in the intertidal zone from Bay of 

 Fundy to northern Florida and on the Gulf coast 

 westward to Texas. Locally common and often 

 gregarious. 



Differs from all other species on this coast by 

 its capacity for asexual reproduction by fragmen- 

 tation (Coe 1930). If the body is cut into many 

 small pieces each fragment will ordinarily regen- 

 erate into a minute replica of the original worm. 

 For complete regeneration the fragment must con- 

 tain a portion of one of the nerve cords. This is 

 excellent material for such studies, since the worms 

 or their fragments may live for a year or more in 

 jars of sea water with pebbles in the bottom pro- 

 vided the water is changed occasionally (Coe, 

 1929-34). A period of asexual reproduction may 

 be followed by dioecious sexual reproduction in 

 which the sexes mate and the eggs are deposited 

 in a thick mucous sheath. 



Micrura leidyi Coe, 1943 



Meckelia rosea Leidy, 1851; Cerehraiulus leidyi Verrill, 

 1892. 



One of the most common of the species of ribbon 

 worms in the Gulf and along the east coast of the 

 United States. The body is rather slender, 

 cylindrical in anterior portion, and much flattened 

 in intestinal region; very fragile; head slender, 

 without ocelli; caudal cirrus small; color deep red 

 or purplish red, lighter anteriorly; anterior border 

 of head and mouth region whitish; length 20 to 

 300 mm., width 1 to 6 mm. 



Lives in sand and under stones in the intertidal 

 zone and in shallow water from Massachusetts 

 Bay to the coast of northern Florida and in the 

 Gulf west to Texas. Individuals of this species 

 are among the most fragile of all nemerteans and 

 usually break into many pieces when lifted from 

 the sand. The numerous eggs, which are excellent 

 for embryological studies, are shed into the water 

 from July to October on the coast of southern New 

 England, but the season of reproduction in the 

 Gulf is not at present known. The larvae can be 

 reared to the pilidium stage without difficulty. 

 The adult worms have the capacity for the rapid 

 posterior regeneration of fragments from the 

 anterior part of the body, but if the head is 

 removed it is seldom, if ever, regenerated. 



Cerebratulus ater Verrill, 1895; Coe, 1943 



Meckelia atra Girard, 1851. 



This species is known from a single specimen 

 dredged in deep water off the Cape of Florida, 

 together with two headless fragments which pre- 

 sumably belonged to the same species from near 

 Curasao. The body is uniformly black in color 

 except for the pale anterior extremity. 



Cerebratulus lacteus Verrill, 1892; Coe, 1943 



Mecklia lactea Leidy, 1851; M. ingens Verrill, 1873. 



The body is long and ribbonlike, with flattened 

 intestinal region and thin lateral margins; well 

 adapted for swimming. Ocelli absent; caudal 

 cirrus slender. 



Mature individuals are larger than any of the 

 other nemerteans found on the Gulf coast, often 

 exceeding a meter in length. Color variable; 

 whitish, pale yellow, flesh color, pale red or salmon. 

 Young individuals are usually translucent white, 

 with pale yellow or brown intestinal diverticula. 



This is a common species, burrowing in the mud 

 or sand in the intertidal zone from Maine to 



