NO. 13 coe: revision of the nemertean fauna 261 



12a. Baseodiscus delineatus var. curtus (Hubr.) 



Polia curta Hubrecht, 1879; Eupolia curta Burger, 1895. 



This variety differs from the typical form of B. delineatus in having 

 the body less slender and in having the markings composed of small red 

 or brown dots or larger mottlings without definite pattern instead of 

 interlacing longitudinal lines. The two varieties are often associated. 



Distribution. Of world-wide occurrence; Mediterranean, East Indies, 

 Polynesia, Mauritius, Bermuda, West Indies, on the Pacific coast in 

 the Gulf of California, and on the coast of Chile. 



13. Baseodiscus mexicanus (Biirger), 1895 



(Plate 26, figs. 24-26) 



Eupolia mexicana Burger, 1895; Taeniosoma mexicana Coe, 1905; Jou- 

 bin, 1905. 



Body. Long and slender, moderately flattened even when contracted; 

 usually twisted and knotted into tangled mass ; head demarcated by annu- 

 lar constriction ; body very firm and not easily ruptured. 



Size. Usually about 20-80 cm in length, occasionally up to 2 m or even 

 4 m; 2-10 mm or more in width; body when contracted about half as 

 long as when living. 



Ocelli. Small and numerous, in elongated cluster on each antero- 

 lateral surface of head. 



Color. Brownish green, maroon, deep red, mahogany, or brownish 

 violet, with numerous white rings encircling body at irregular intervals; 

 head usually bordered anteriorly and laterally by narrow horizontal 

 white band. The number of white rings may exceed 300 in a large indi- 

 vidual. In most specimens the white rings are very thin on ventral surface 

 and often incomplete in the midventral line. Some partial rings are usu- 

 ally situated dorsolaterally in the spaces between two complete rings. 

 The thickness of the rings and their distance apart vary with the state 

 of contraction of each region of the body. 



This species has been reported previously from the Gulf of California, 

 west coasts of Central America and Panama, and from the Galapagos 

 Islands. It was collected by the Allan Hancock Expeditions at Ballena 

 Bay, Espiritu Santo Island, San Francisco Island, and Agua Verde Bay, 

 Lower California, Mexico; Black Beach Anchorage, Charles Island, 

 Cartago Bay, Albemarle Island, Darwin Bay, Tangales, Bahia Honda, 

 Taboga Island, Panama, and Coconut Beach, Colombia. Several of 



