170 UNITED STATES NATIONAL MUSEUM BULLETIN 251 



dark yellowish, inner surface whitish. Three remarkable longitudinal 

 grooves on surface on each side. Outer side of mantle grayish yellow 

 brown, inner side and viscera dark brownish. Arrangement of inner 

 longitudinal vessels of branchial sac (D== dorsal, V= ventral) : 



Left D 4 (21) 8 (24) 9 (23) 7 (19) 9 V 



Right D 5 (22) 7 (23) 8 (23) 6 (16) 4 V 



Transverse vessels arranged (numerals represent order of thickness) : 

 13332333 1. Parastigmatic vessels absent, 10-15 stigmata in each 

 mesh. Tentacles 26, larger and smaller ones discernible. Ciliated 

 groove abnormal in appearance (fig. 68). Many amphipods found in 

 branchial sac. 



84. ?Polycarpa quadrata Herdnian 



Figure 69 



PoJijcarpa quadrata Herdman, 1882, p. 173. pi. 22, figs. 8-10.— Traustedt, 1885, 



p. 48.— Tokioka, 1952, p. 123, fig. 21. 

 Stycla quadrata Sluiter, 19(W, p. 126. 

 Pandocia quadrata Van Name, 1918, p. 99, figs. 50-52; pi. 31, fig. 34. 



MATERIAL EXAMINED 

 Palau Islands : Iwayama Bay, east side of Oyster Pass. GVF sta. 220. Two 

 specimens (USNM 11442). 



Description. — Two small specimens from the Palau Islands were 

 examined. They are 4 mm. (fig. 69a) and 3.5 mm. (fig. 69Z>) in length, 

 the former accompanied by two very small individuals found at- 

 tached to its surface, and the latter with a single minute individual 

 attached to the posterior end of the body. 



Body ovate or elongate-elliptical, branchial aperture terminal, 

 atrial aperture situated near branchial. Test yellowish white, trans- 

 lucent, wrinkled, carries sand grains and mud on surface. Mantle 

 rather thick, purplish brown. Atrial tentacles very distinct. Several 

 remarkable endocarps on inner surface of mantle. In branchial sac 

 inner longitudinal vessels arranged (D= dorsal, V= ventral) : 



Left D 2 (9) 1 (10) - - - (4) 1 V 



Right D ? (8) 1 (7) 1 (9) 1 (4) 1 V 



Transverse vessels nearly of same thickness, parastigmatic vessels 

 absent. One or two stigmata in each mesh. Tentacles 22, larger and 

 smaller ones differentiated. Ciliated groove T-shaped. Second intes- 

 tinal loop very shallow, axis passes approximately esophageal region. 

 Stomach oval in outline, eight longitudinal plications on free sur- 

 face, a caecum at inner pyloric corner. Anus divided into two lips. 

 Gonads not yet developed. 



Remarks. — The general appearance of the alimentary canal of the 

 present specimens shows close relationship to Polycarpa quadrata 

 Herdman, though the identification is not definite, as no gonads are 

 developed. 



