Comprehensive DescriptionRead full entry
(from Coe, W. R. (1905). Nemerteans of the west and northwest coasts of America.. Bull. Mus. comp. Zool. Harv.. 1-318)
Body moderately slender; head very long and acutely pointed, without lateral furrows ; cerebral sense organs well developed, connected with exterior by ciliated duct opening into shallow pit on lateral margin of head ; ocelli wanting ; caudal cirrus conspicuous, with large central blood space connected both with lateral and with dorso-median vessels. Proboscis sheath extends throughout length of body; proboscis with but two muscular layers - outer longitudinal and inner circular ; proboscis without retractor muscle.
As stated by Miss Thompson this genus undoubtedly belongs to the family Lineidae. The absence of lateral cephalic furrows is not of very fundamental importance. Different species of the same genus sometimes show nearly all gradations between deep horizontal furrows and merely slight lateral grooves or pits into which the canals from the cerebral sense organs open. Cerebratulus coloratus Buerger is an example of such a form in which lateral horizontal furrows are practically wanting, while other members of this same genus have the most highly developed furrows of any nemerteans.