536 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. 54. 



Gastral triradiates {d} sagittal, rather slender-rayed. Basal ray 

 straight, much longer and slightly thinner than paired ray, nearly 

 uniformly thick throughout, except at the thickened basal parts and 

 the tapering and sharply pointed end, sometimes slightly narrowed 

 in the middle parts, 350-500 \i. long and 12 [i thick at base. Paired 

 rays slightly irregular in outline, curving first backwards and then 

 slightly forewards, about 190 \j. long and 16 \i thick at base. 



Fig. 4. — Geantia nipponica. a, dermal tbieadiates. 6, tubae teieadiates. c, sub- 



GA.STRAL TRIRADIATE. d, GASTRAL TRIRADIATE. 6, GASTRAL QUADRIRADIATE. e', APICAL 

 RAY OF GASTRAL QUADRIRADIATE. f. QOADRIRADIATES OF EXHALANT CANALS. f, SAME 

 SEEN FROM LATERAL SIDE. g, TRIRADIATE OF OSCULAR COLLAR. h, QUADRIRADIATE OF 

 OSCULAR COLLAR. i, OXEA PROJECTING FROM DERMAL SURFACE. j, OXEA OF OSCULAR 

 COLLAR. All X150. 



Gastral quadriradiates (e) similar to the gastral triradiates, dif- 

 fering only in the presence of apical ray. Apical ray (e') varying 

 considerably in length, slightly curved upwards and occasionally 

 at the same time crooked, nearly uniformly thick in the greater 

 part of its length, but narrowed in the basal parts and at the pointed 

 end, 330-700 \l long and 16 [x thick in the middle parts. 



Quadriradiates of exhalant canals (/) small. Basal ray nearly 

 straight, gradually tapering to sharp point, about 110 [;, long and 10 \i, 



