REPORT ON THE NEMERTEA. 



33 



" Postscript. — Since the above was written, my attention has been directed by 

 Dr. von Willemoes Suhm to Lesson's original figure of Pterosoma in tlie ' Zooloo-y of the 

 Voyage of the Coquille ' (which work we have been able to consult, with a splendid series 

 of similar publications, in the Hawaian Government Library at Honolulu), and to the 

 many points of resemblance between Pterosoma and Pelagonemertes. 



Fig. 3. — Pdagonemertes rollestoni, Moseley, enlarged, viewed from the dorsal surface ; the proboscis is partly extruded. 

 P, proboscis ; PrS, sac of proboscis ; IP, invaginated portion of proboscis within the proboscis-sac ; G, superior nerve- 

 ganglion ; NC, nerve-cords ; V, vascular trunk (the upper V points to an enlargement of the vessel lying just 

 posteriorly to the superior nerve-ganglion) ; I, intestine ; D, diverticula of intestine ; 0,0, ovaries ; CM, circular 

 muscles ; LM, longitudinal muscles. 



" Pterosoma plana is described by M. Lesson, ' Voyage de la Coquille, Zoologie,' 

 Paris, 1830, p. 254, and figured, pi. iii. figs. 3 and 3 Us. Pterosoma was obtained in 

 great abundance by Lesson between the Moluccas and New Guinea, August 31, 1828. 



"The animals measured 3 inches and some lines in length, 18 lines in breadth, and 

 3 to 4 lines in thickness. In general form and gelatinous structure Pterosoma resembles 



(ZOOL. CHALL. EXP. — PAET LIV. — 1886.) H'lli ^ 



