PACIFIC TUXICATA OF U.S. NATIONAL MUSEUM 213 



wliite to brownish, dorsal side partly dark brownish. Inner surface of 

 test whitish to pale brownish. Surface wrinkled and often carries 

 tine mud. Spinules on inner surface of distal portion of siphons very 

 minute and somewhat conical in shape. Mantle of considerable thick- 

 ness with well-defined nuisculature consisting of longitudinal and 

 transverse nuiscles. Coloration yellowish w^hite to yellowish brown or 

 brownish to reddish brown. Minute villus-like protuberances occur 

 sparsely on atrial velum and also on soft inner surface of basal portion 

 of siphons. Brancliial plications 7 (8 nnn. long individual) to 9 on 

 left and 8 or 9 on right side. Ventralmost fold on left side rudimen- 

 tary in some specimens. 



The Australian specimen show^s following arrangement of inner 

 longitudinal vessels : 



Left D 1 (19) 1 (13) 2 (17) 2 (17) 2 (14) 2 (15) 1 (13) 1 (12) (3) V 

 Right D 1 (16) 1 (14) 1 (19) 1 (18) 2 (16) 2 (13) 1 (12) 1 (12) (7) V 



The 16 mm. long specimen from the Gilbert Islands shows following 

 arrangement: 



Left D 3 (18) 2 (15) 2 (19) 2 (18) 2 (18) 2 (16) 1 (15) 1 (11) V 

 Right D 2 (14) 1 (15) 1 (21) 1 (20) 1 (17) 1 (16) 2 (13) 1 (12) 1 (9) V 



Transverse vessels arranged: 1 p2p1, orl p3p2p3p1. 

 Six to nine elongated stigmata in each mesh. Tentacles rather simple, 

 with branches in two (Saipan specimens and one of the Gilbert Islands 

 specimens) or three (Australian specimen and one of the Gilbert 

 Islands specimens) orders. Tentacles 18-20, large and small, also 

 some minute ones at intervals. Second intestinal loop distinct; axis 

 does not seem to pass through middle of ventral branch of first in- 

 testinal loop, but rather bottom of second loop seems to touch or 

 reach near hepatic region of ventral branch. Anal margin plain. 

 Three endocarps on intestimil wall just posterior to hepatic region in 

 the 16 mm. long specimen; no such appendages found in other speci- 

 mens. Liver yellowish brown in preserved specimens. Two to six 

 genital capsules on left and two to seven on right side; capsules placed 

 rather closely to each other so that gonad in some specimens looks 

 as if it consisted of only a single mass irregularly lobated into a few or 

 several lobes. 



Hemakks. — The differences between the Amoy specimens and those 

 from Saipan, the Gilbeit Islands, and Port Jackson are considered to 

 be insignificant as specific characteristics. However, the dill'erences 

 found in the branching order of the branchial tentacles, the feature 

 of the second intestinal loop, and in the appearance of the gonad are 

 rather noteworthy. It is not impossible that the last two of the three 

 differences are attributable to body size of the specimens, although 

 such differences may be clearly observed between a certain small speci- 

 men from Amoy (i;> mm. long) and Saipan and Australian specimens 

 (8-17 mm. long). The first of tlie three differences, however, seems 



