178 UNITED STATES NATIONAL MUSEUM BULLETIN 251 



vessels in a dissected 33 mm. long individual arranged as follows 

 (D = dorsal, V= ventral) : 



Left D (20) 5 (21) 5 (21) 5 (18) 5 V 



Right D 1 (11) 5 (19) 6 (21) 6 (20) 5 V 



Transverse vessels arranged — thick thin medium thin thick — or these 

 are further intervened by parastigmatic vessels in some places. From 

 3 to 5 stigmata in each mesh, may be up to 9 in larger meshes along 

 endostyle. Tentacles up to 19, larger and smaller ones differentiated ; 

 edge of dorsal lamina plain. Ciliated groove somewhat complicated. 

 Second intestinal loop very shallow; when loop is deep enough, its 

 axis passes through esophageal region. Stomach oval; plications 

 rather distinct on attachment side (fig. 73c) while free surface is quite 

 smooth, although about 7 folds seen faintly on inner wall. Anal mar- 

 gin cut into about 20 lobules. Gonads, 24 on left and 24-29 on right 

 side in examined specimens, usually a single gonad in first intestinal 

 loop. Gonads elongated ; testicular follicles increase in number with 

 size and are arranged roughtly in two rows on attachment side. 



89. Polycarpa melanosiphonica, new species 



Figure 74 



HoLOTYPE.— USNM 11499: Gilbert Islands; Onotoa Atoll. A. H. 

 Banner, sta. A XVI, August 24, 1951. 



Parattpe. — USNM 11508: Marianas Islands; lagoon west of Sai- 

 pan, at entrance to Tanapag Harbor; attached to surface of a large 

 dead coral, from i/^-ton block brought up on anclior of L.T. 535, 

 Capt. Ted Han-is. P. E. Cloud, location 2, April 28, 1949. 



Description. — A 17 mm. long specimen from the Gilbert Islands 

 and a 14 mm. long individual from Saipan Island are described. 

 Animal attached to substratmn by posterior end or right ventral 

 side of body. Branchial aperture terminal, atrial situated with its 

 posterior margin at middle of body, both apertures nearly sessile. 

 Test leathery, very tough, irregularly folded and strongly wrinkled 

 over surface, attains 1 mm. thickness in some places; pale yellow^ish 

 brow^n, areas around apertures somewhat whitish, each marked with 

 four purplish-brown color bands converging to respective apertures, 

 each band consists of several fine colored stripes. Inner surface 

 somewhat paler with pearly glistening. Mantle yellowish white, 

 moderately thick; both siphons short and darkly pigmented in pur- 

 plish black (fig. 74:g) ; viscera also yellowish white. Many elongated 

 endocarps scattered oA^er inner surface of mantle, larger ones faintly 

 pigmented in purplish brown. Fine tentacles on atrial velum. 



In branchial sac imier longitudinal vessels are arranged (D = dorsal, 

 V= ventral) : 



Left D 1 (10) 2 (10) :\ (10) S (8) 2 V 



Right D 1 (9) 3 (10) 3 (11) 1 (12) 2 V 



