304 bulletin: museum of comparative zoology. 



Habitat. — Known only from Kadiak, Alaska, where a few speci- 

 mens were dredged at a depth of about 3 fms. Possibly parasitic 

 in tunicates or other invertebrates. 



Planktonemertes Woodworth. 

 Bull. Mus. Comp. Zool., 35, p. 2, 1899. 



Woodworth's diagnosis of this genus of pelagic nemerteans is as 

 follows : — 



"A common external opening for the mouth and proboscis. 

 Supraoesophageal ganglia smaller than suboesophageal. Median 

 dorsal vessel present. Lateral diverticula of the intestine very 

 numerous." 



• To this diagnosis the family characters of the Pelagonemertidae 

 of Moseley to which the genus belongs may be added : " Pelagic 

 nemerteans with broad, flattened, leaf-like, gelatinous, very hyahne 

 body. Rhynchocoel extending nearly the entire length of the body. 

 Proboscis unarmed. No cephalic grooves or organs of special sense. 

 Intestinal tract dendrocoelous." 



85. Planktonemertes agassizii Woodworth. 

 Bull. Mus. Comp. Zool., 35, pp. 1-4, with 1 plate, 1899. 



This very remarkable pelagic nemertean is represented in these 

 collections by a single specimen taken by the Albatross at Sta. 

 2792 (Lat. 0° 37' S., Long. 81° W.). This station is off the coast of 

 Ecuador, and hardly comes within the limits covered by this report, 

 but the species is mentioned here because other specimens have 

 been collected off the coast of Panama. P'ive specimens have 

 already been described in a preliminary paper by Woodworth ('99). 



Body oval in shape, very much flattened, hyaline, with parallel 

 undular sides, rounded at both ends. 



Length of the six specimens known varies from 14 to 47 mm. ; 

 greatest width 16 ram. ; thickness only 1 to 2.5 mm. Average 

 length about two and one half to three and one half times as great 

 as width. 



Color orange, pink, or scarlet, the intestinal diverticula and pro- 

 boscis being of deeper color. 



