180 bulletin: museum of comparative zoology. 



the body, or may be considerably narrower. In the latter case they 

 are bordered laterally on the dorsal surface by a narrow band of 

 white, continuous with that of the ventral surface. On dorsal 

 surface of tip of snout is a very conspicuous triangular marking of 

 bright orange color (PI. 3, figs. 34, 35). Following this pos- 

 teriorly is a narrow, transverse white line ; then comes a series of 

 broad purple rectangles and narrow white lines in succession. 

 There are usually '20 to 40 of these rectangles. As a general 

 rule, the second, fourth, and sixth rectangles are shorter antero- 

 posteriorly than the first, third, fifth, etc. The comparative length 

 of the rectangles is naturally dependent upon the state of con- 

 traction of the body. 



Ventral and lateral surfaces of body pure white. 



Proboscis of three muscular layers; with distinct crossings of 

 fibers. 



Nephridia extensive, occupying anterior two thirds of esophageal 

 region, and provided with numerous (15 to 20 or more) efferent 

 ducts. 



For further details of anatomical peculiarities, see Coe, :01 or :04, 

 pp. 68-70. 



This handsome species is found quite commonly at Pacific Grove 

 and Monterey, California. In addition to the description given in 

 the paper quoted above, the following notes on the specimens found 

 in California may be added. In general these individuals differ 

 from those collected in Alaska in having the dorsal markings much 

 narrower than the body, so that a narrow margin of ivory white 

 color is seen on each side when the worm is viewed from the dorsal 

 surface (PI. 3, figs. 34, 35). Sometimes the purple markings are 

 not more than three fourths or even one half as wide as the diam- 

 eter of the body, and a few individuals in which the genital products 

 were mature were observed to have the dorsal markings covering 

 only the median third of the dorsal surface in the intestinal region. 

 The lateral white color is more opaque than the white of ventral 

 surface, and in it is a row of slightly grayish dots on each side in 

 intestinal region. These apparently represent the genital pores, for 

 they seem to be limited to the sexually mature individuals. They 

 are sometimes quite conspicuous (PI. 3, fig. 35). 



Even in small individuals there are seldom less than 30 of the 

 rectangular purple markings, while specimens attaining a length of 



