28 COK 



Their ducts lead directly to the surface of the body, and consequently 

 open at any point instead of in certain definite regions as in many 

 species. 



Both lateral nerves and blood vessels join above the hind gut as in 

 most other Nemerteans — the union of the nerves lying ventral to that 

 of the blood vessels. 



This species is named in honor of Prof. Dr. Otto Burger, of Got- 

 tingen, whose monograph on the Nemerteans of the Gulf of Naples 

 forms by far the most important contribution which has yet appeared 

 relating to this group of worms. 



Habitat. — Several individuals are often found knotted together in a 

 seemingly inextricable mass. The body lies coiled in a mass, and is 

 bent and folded in sharp angles. 



The species was found under mussels on rocks between tides at 

 Glacier Bay (W. E. Ritter) and at Sitka. 



Zygonemertes Montgomery. 

 Zool. Jahrb., x, p. i, 1897. 



A species of Nemertean was found at Sitka which agrees very 

 closely with Verrill's description of Amphiporus virescens.^ The 

 detailed anatomical description given by Montgomery,' however, shows 

 at once that the Alaska Nemertean is a distinct species. Mont- 

 gomery has created a new genus for A. virescens Verrill based on its 

 anatomical peculiarities, especially the structure of the proboscis and 

 proboscis sheath. This genus he named Zygonemertes ., with the 

 following characters as its chief peculiarities : 



(i) The proboscis sheath reaches to the end of the body, while (2) 

 the thickened proboscis is but half as long; (3) basis of central stylet 

 large, elongated ; flattened or slightly concave posteriorly ; (4) central 

 stylet massive, not half the length of its basis : (5) ten or eleven pro- 

 boscidial nerves ; (6) body contractile, shape like Amphiporiis^ not 

 as elongate as in Emplectonema ; (7) ocelli numerous and small, ex- 

 tending along the nerve cords posterior to the brain. 



While I am of the opinion that these characters are mainly of spe- 

 cific rather than of generic rank, yet I am convinced that because of 

 the large number of species already in the genus Ampkiporus the 

 establishment of this new genus will be of great practical convenience. 

 The most tangible characters of the group are : ( i ) the eyes extend 

 posteriorly beyond the brain along the lateral nerve cords, and (2) the 



'Trans. Connecticut Acad., viii, p. 20, 1892. 

 'Zool. Jahrb., x, p. 2 to 4, 12, 1897. 



