214 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 



fornia coast are in the number of proboscidial nerves and the char- 

 acter of the armature of proboscis (see p. 

 215). It is possible that collections in 

 intermediate localities, as Puget Sound, 

 will bring to light forms M'hich show an 

 intergradation between these two sup- 

 posed species, thus uniting them into a 

 single s])ecies showing considerable varia- 



FiG. 35.~ Zygonemertes tha- . . j? i ■ 



lassina. Accessory stylets. tion in Structure ot proboSClS. 



45. Zygonemertes virescens (Verrill) Montgomery. 



Amphiporus virescens Verrill, Proc. U. S. Nat. Mus., 2, p. 183, 

 1879; Trans. Conn. Acad., 8, p. 400, PI. 33, figs. 4-4e, 1892. 



Zygonemertes nirescens Montgomery, Zool. Jahrb., Syst., 10, |). 2, 

 1897. 



PI. 22, figs. 141-144. 



This common New England species occurs in considerable num- 

 bers on the piles of wharves in the harbors of Monterey, San Pedro, 

 and San Diego, California. 



It may be recognized by the following characters : — Body slen- 

 dei", rather depressed, head variable in shape, often wider than parts 

 immediately following, provided with two })airs of oblique furrows 

 as usual ; anterior pair of furrows situated about half-way between 

 brain and tip of snout when moderately extended, conspicuous on 

 lateral margins when head is somewhat compressed. 



6'ize. — The individuals collected in California were all of small 

 size, although sexually mature. They measui'ed only from 5 to 20 

 mm. in length, and were usually from 0.5 to 1 mm. wide. On the 

 coast of New England the same species may become 40 mm. long, 

 although the usual size is 25 mm. or less. 



Color.- — Usual color pale green, although some individuals, 

 especially when immature, are flesh colored anterioi-ly, becoming 

 pale green towards intestinal region, while others are yellowish 

 green or pale olive green throughout. A few of the smaller indi- 

 viduals found at Monterey were cream colored in life, but assumed 

 a greenish tinge after preservation. When examined with the 

 microscope, numerous yellowish sickle-shaped bodies are seen to lie 



