NEMERTEANS 127 



white with shield-shaped or triangular marking of 

 deep brown color on dorsal surface. Body deep 

 purple, deep brown with white dorsal longitudinal 

 band, reddish with brown flecks, pale brownish or 

 buff on dorsal surface ; of similar color, but paler, 

 and often with white longitudinal band on ventral 

 surface. Blood corpuscles red. 



T. nigrifrons, p. 159. 



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



grayish, with two deep brown longitudinal stripes 

 on dorsal surface T. bilineatum, p. 164. 



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



deep brown longitudinal stripes, of which two lie 

 on lateral margins and two on dorsal surface. 



T. quadrilineatum, p. 166. 



5. Firm, cylindrical, slender, body only 8 to 15 mm. in 



length ; flesh color or yellowish, mottled, especially 

 on dorsal [surf ace, with brownish blotches and dots 

 of various shades, often mainly collected into a 

 series of transverse bands. 



T. {Oerstedia) dor sale, p. 169. 



6. Firm, cylindrical, slender, 8 to 15 mm. in length. 



White, with large rectangular and longitudinal, 

 dark brown markings almost covering dorsal sur- 

 face. Often with sixteen pairs rectangular marks 

 and pair of lateral brown lines in addition to bi- 

 lobed marking on dorsal surface of head. In some 

 varieties markings fuse together. 



T. (Oerstedia) reticulatum,^. 170. 



Order Heteronemertea. 



A. Head without deep, lateral, longitudinal furrows. Proboscis 

 musculature of two layers, an outer circular and inner longi- 

 tudinal layer, without muscular crossings Ttzniosoma. 



i. Body large, soft, flabby, 40 to 60 cm. or more in length. 



Color brownish red or mahogany ; tip of snout darker 



brown with terminal white border ..T. punnetti, p. 173. 



AA. Head without deep, lateral, longitudinal furrows. Cerebral 



sense organs open into pit on margins of acutely pointed 



head. Proboscis musculature of two layers, outer longi- 



