226 UNITED STATES NATIONAL MUSEUM BULLETIN 251 



sessile, and open on a slightly elevated dorsal ridge, being 8 mm. apart 

 in a 23 mm. long individual (fig. 1035). No rooty protuberance 

 (rhizom) found on present specimens. About 30 (29-32 in examined 

 specimens) rather thick transverse muscles on each of anterior and 

 posterior one-third of body, a number of fine transverse muscles cover 

 dorsal side of body between both apertures and extend ventrally near 

 middle of body, being interrupted once or twice on their way (fig. 

 103c). Longitudinal muscles covering dorsal half of body are 

 beneath transverse musculature; about 30 on posterior half con- 

 verge at atrial aperture, and about 25 anterior ones gather at 

 branchial aperture. Around both apertures, longitudinal muscles 

 run outside siphonal sphinctors. A small mantle prominence, 

 somewhat cup-shaped in examined specimens, at ventral apex of 

 body, approximately at level of one-third the body length from 

 posterior end of body. Evidently this is liomologous with that 

 found at base of rhizom in Harfmeyeria orwntalis Oka. Spinules 

 on inner surface of siphons are peculiar in shape, being trifid at tip 

 (figs. lOda-c). Those on the proximal part of the siphon are all laid 

 nearly horizontally, 38-50/j, in length in examined specimens; those 

 from distal part somewhat like hemispherical elevations on sur- 

 face, each ending in three fine spinules, about 36/* in height from base 

 to tip of spinules. 



In branchial sac tentacles 28-33, arranged in order: large-small- 

 large or large-small-medium-small-large; branched very compli- 

 catedly, branches in three orders. Ciliated groove (figs. 103.7, ^) 

 U-shaped, mth both horns usually curled in or sometimes curled out. 

 Six folds on each side of branchial sac, second fold rudimentary and 

 represented by only a single longitudinal vessel. Inner longitudinal 

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



15 mm. long individual 



Left D (13) (1) (11) (11) 



Right D (14) (1) (12) (11) 



23 mm. long individual 



Left D (15) (1) (13) (12) 



Right D (16) (1) (12) (12) 



Transverse vessels arranged: 1 333 2 333 1 or 

 merals indicate order of thickness of vessels). Extremely fine para- 

 stigmatic vessels at some places. Four infundibula between each 

 pair of thicker vessels of first order, namely two between vessels of 

 first and second orders. Tip of each infundibulum divided into two 

 apexes. Stigmata elongated and generally extending between vessels 

 of first and second orders, although often interrupted irregularly 

 and complicatedly. Dorsal lamina plain membrane. 



Liver consists of a longitucHnally plicated anterior lobe and a 

 posterior half consisting of many oval lobules of olive green, each with 



