COE: NEMERTEANS OF WEST AND NORTHWEST COASTS. 215 



in the outer integument, and in addition there are numerous radiating 

 bhiish green pigment granules in the same layer, but situated very 

 superficially. Intestinal canal sometimes pale orange ; matiire ova 

 greenish. Some individuals are yellow rather than green on ventral 

 surface, although both surfaces are usually of about the same color. 

 Greenish tinge retained for a long time after preservation, or reap- 

 pears after such specimens are placed in clearing oil. 



Ocelli. — Head provided with numerous ocelli, which extend 

 posteriorly far beyond the brain. There are commonly 20 to 60 

 rather small ocelli on each side of head, arranged in two parallel, 

 but very irregular, clusters (PI. 22, fig. 141) on each side, and 

 extending back as far as the brain. Behind brain are usiially 4 to 

 12 smaller ocelli situated at irregular intervals in a single row along 

 lateral nerve cords. The brain is situated about half-way between 

 tip of snout and most posterior ocelhxs. 



Proboscis. — Sheath extends to posterior end of body, although 

 proboscis is little moie than half as long. Armature consists of 

 short central stylet with large, cylindrical basis about 1^ times as 

 long as stylet itself (PL 22, figs. 142, 144). Stylets ai"e not acutely 

 pointed, nor are they as stubby as in Z. thalassina. Basis is some- 

 what narrowed near posterior end, which is commonly notched or 

 longitudinally grooved (PI. 22, fig. 142). Length of basis commonly 

 0.12 to 0.16 mm., width about one third as great ; length of stylet 0.08 

 to 0.1 mm. There is a much greater range of variation, however, 

 than these figures indicate. The two lateral pouches usually contain 

 2 or 3 stylets each (PI. 22, fig. 143). Wreath of gland cells about 

 stylet region of proboscis and basis of central stylet sometimes 

 bluish green after preservation. There were 11 proboscidial nerves 

 in each of five specimens sectioned, although one other individual 

 had but 10. In New England specimens 10 is the usual number. 



Internal anatomy.^ — Cerebral sense organs large, situated imme- 

 diately in front of brain. Intestinal caeca extend to posterior bolder 

 of dorsal brain lobes. Nephridia situated in brain region and imme- 

 diately posterior thereto ; a single pair of efferent ducts open on 

 latero-ventral surfaces of body immediately behind the brain or in 

 the posterior brain region. 



A terminal sense organ is situated directly above the rhynchodaeal 

 opening. 



' For further details, see Montgomery, '97, p. 2. 



