62 COE 



are prone to twist themselves in sharp coils, or in knots, and often lie 

 in lumps. They are usually capable of contracting and extending their 

 bodies to a remarkable degree. 



22. TVENIOSOMA PRINCEPS sp. nov. 

 pi. n, figs. 3, 4. 



Body of very large size, long, thick, largest in the esophagal region, 

 cylindrical in anterior portion, flattened on ventral surface posteriorly ; 

 in contraction nearly cylindrical throughout. Head sharply marked off 

 from body in extension, rounded in front, flattened dorso-ventrally ; in 

 contraction drawn almost entirely into the parts immediately following, 

 so that the anterior portion of the body is greatly swollen and sharply 

 truncated in front. In contraction the anterior end of the body is 

 thrown into massive folds, and the whole body is remarkably short 

 and thick (pi. n, fig. 4). A pair of inconspicuous, oblique grooves 

 lies on the antero-ventral surfaces of the head ; into these the canals 

 leading from the cerebral sense organs open. The esophagal region is 

 scarcely more than one-twelfth the length of the body. In alcoholic 

 specimens there is usually a median ridge on the dorsal surface run- 

 ning the length of the body, except in the head and esophagal regions. 



Color. The dorsal surface is deep ochre yellow, sometimes inclin- 

 ing to orange, and sometimes to brownish, and thickly strewn with 

 minute irregular dark red spots. The reddish markings are most con- 

 spicuous near the anterior end of the body, and in the dorsal, median 

 line. In many places a large number of the reddish dots become con- 

 fluent, and form an irregular patch of deeper color. These patches 

 commonly occur as broken longitudinal lines. Such lines are most 

 abundant on the middle of the dorsal surface where they form a median 

 longitudinal band of reddish-brown. The ventral surface is paler and 

 the reddish markings are wanting. Along the median line the color is 

 brighter yellow than elsewhere on the ventral surface. This is appar- 

 ently due to the absence in this position of the opaque intestinal lobes. 

 The ventral surface often exhibits a greenish tinge to the yellow ground 

 color. The posterior extremity is pointed and much paler than the 

 rest of the body. 



Size. T. princeps grows to a size greater than has previously 

 been described for any species of the genus. The individuals found 

 were from half a meter to two meters in length when extended ; when 

 contracted, but a small fraction of this length, and proportionately 

 thick (pi. n, fig. 4). After long standing in alcohol a section of the 



