COE: NEMERTEANS OF WEST AND NORTHWEST COASTS. 107 



2. Rather slender, 15 to 25 mm. in length; reddish 



brown both above and below, except head, 

 which is white with a sharply marked wreath 

 of deep brown color on dorsal surface ; blood 

 corpuscles red . . . T. signifer, p. 287. 



3. Usually 20 to 70 mm. in length ; head provided 



with two pairs of very conspicuous, lateral, 

 oblifpie furrows. Color very variable, except 

 head, which is white with shield-shaped or tri- 

 angular marking of deep brown color on dor- 

 sal surface. Body deep purple, deep brown 

 with white dorsal longitudinal band , reddish with 

 brown flecks, pale brownish, or bixff on dorsal 

 surface ; of similar colors, but paler, and often 

 with white longitudinal band on ventral surface. 

 Blood corpuscles red. . T. nigrifrons, p. 289. 



4. Body very slender, usually 10 to 15 mm. m length ; 



color milk white, creamy or flesh colored ; basis 

 of central stylet very slender ; cerebral sense 

 organs remarkably large, situated beside brain. 



T. albichim, p. 294. 

 cc. With distinct longitudinal brown stripes on dorsal 

 surface . 



1. Only 5 to 10 mm. in length ; flesh color, creamy or 



grayish, with 2 deep brown longitudinal stripes on 

 dorsal surface. . • . 7\ hil'meatum, p. 296. 



2. Usually 8 to 12 mm. in length ; whitish, with 4 deep 



brown longitudinal stripes, of which 2 lie on lat- 

 eral margins and 2 on dorsal surface. 



T. ijiiadri/inedtum, p. 297. 

 bb. Body remai'kably firm, cylindrical. (Oekstedia.) 



1. Body slender, only 8 to 15 mm. in lengtli ; flesh color 



or yellowish, mottled, especially on dorsal surface, 

 with brownish blotches and dots of various shades, 

 often mainly "collected into a series of transverse 

 bands. . . T. ( Oersted ia) dorsale, p. 299. 



2. Body slender, 8 to 15 mm. in length ; white, with 



large, rectangular and longitudinal, dark brown 

 markings almost covering dorsal surface. Often 

 w ith l(i pairs of rectangiilar marks and pair jsf lateral 

 l)rown lines in addition to bilobed marking on dor- 

 sal surface of head. In some varieties markings 

 fuse together. T. (Oerstedia.) reticulatum, p. ;]00. 



