176 UNITED STATES NATIONAL IVIUSEUM BULLETIN 251 



especially a few longitudinal grooves are prominent ; frequently fouled 

 with various organisms. Test usually grayish white or brownish, 

 although some specunens may be as dark brownish as in Polycarpa 

 cryptocarpa; inner surface grayish white and glistens. Mantle thin 

 but tough, usually dark brownish; viscera also brownish. Minute 

 tentacles along atrial velum. 



In branchial sac inner logitudinal vessels are arranged in two larger 

 specimens as follows (D = dorsal, V= ventral) : 



No. 1 Left D 2 (11) 3 (11) 



Right D 2 (11) 2 (9) 



No. 2 Left D 2 (6) 5 (14) 



Right D 4 (10) 4 (12) 



In 55 mm. long specimen from Palau Islands, a short low rudimentary 

 fold was found in right posterior part of branchial sac between dorsal 

 lamina and the first fold : — D (3) 2 (10) — . Transverse vessels 

 are arranged (numerals represent order of thickness) : 1 3 2 3 1, or 

 14342434 1. Vessels of fourth order are replaced in some speci- 

 mens with parastigmatic vessels which are, however, practically absent 

 in some others. Stigmata 6-8 to 12-15 in each mesh, may be up to 

 15-20 in meshes along endostyle. Tentacles 28-31 in examined speci- 

 mens, usually larger and smaller ones alternate; medium or minute 

 ones may be differentiated in some specimens. Ciliated groove 

 generally simply U-shaped with horns curled in or out. Second in- 

 testinal loop very shallow, axis passing through esophageal part or 

 cardiac portion of stomach, turning portion of loop may be more or 

 less swollen (figs. 72 5, c). Anal margin cut into 20-25 lobules. 

 Usually 02ie large and two smaller endocarps in first intestinal loop. 

 Pyloric caecum absent. Gonads usually distributed in ventral one- 

 third or half of body, most densely along endostyle ; up to 85-180 on 

 right, 67-100 on left side in examined specimens, always buried beneath 

 thin, translucent mantle tissue, distinctly visible from surface as if 

 quite exposed. 



Tadpole larvae found in a 37 mm. long specimen from the Marshall 

 Islands; trunk ellipsoidal, 310-350/* in length, with sensory pigment 

 fleck nearly at middle; three attachment processes, of which two are 

 dorsal and one ventral. Tail twice as long as trunk, tip bluntly 

 pointed. 



88. Polycarpa psammotesta Tokioka 



Figure 73 

 Polycarpa psammotesta Tokioka, 1953a, p. 249, pi. 50, figs. 1-8. 



MATERIAL EXAMINED 



.Japan: Honshu Island; off Ose Zaki, S. 34° E., 0.8 mi. Albatross sta. 3717. 

 Three specimens. — Hokkaido Island ; Hakodate. E. S. Morse, coll. Two speci- 

 mens (USNM 11696). 



